Yes, tested municipal tap water is pure & safe to drink and is more regulated than Perrier. Got it.
But when I was stationed in Germany and went on Volksmarsch, the locals were appalled when I asked for a drink of `Leitungswasser’ (tap water). They gave me bottled water & said don’t worry about paying for it.
Is tap water any purer than in Germany?
I have no idea the condition of tap water in Germany at the time you were stationed there. I know that tap water in USA, AUS, Canada, and UK is generally safe to drink. I even drank the “tap water” in the Canadian “First Nation” village ... even after I found out where it came from. No problems.