[guenthert]

Tap water quality differs from one municipality to another, so I wonder about the value of a map by county. E.g., in Germany the quality is generally good, almost universally safe to drink, but in some rural areas with intense agriculture, the water might be so rich in nitrates, that occasionally (seasonally?) it is recommended that pregnant women and small children drink bottled water.

The taste and suitability to make tea differs wildly w/o impacting health (matter of carbon content). And it's not quite clear to me, whether the amount of chlorine should affect the listed water quality. Some people are sensitive to it, I'm not. And you can always let it sit for a while and the chlorine will evaporate.