Should I have worries drinking rheinländisches Leitungswasser? It tastes namely quite well, so I drink quite a lot of it. Prefer some types of bottled water though, but is the tap water here good enough to not worry?
Even here in Costa Rica, I've been drinking tap water for years and I never got ill from it. BTW, just for curiosity, here's the current link of the most recent water analysis made on the Wasserwerk close to where I used to live, the Wasserwerk Schnelsen of the HWW (now part of Hamburg Wasser). Most of the trace elements were not detectable, while the rest is safely below limits.
Luckily Helsinki has one of the best tap waters in Europe, coming from a huge lake north of the capital.
The very same water is bottled and exported under the trademark 'Nord Water', especially to Saudi-Arabia:
Chinese cookie in SFO: "You're doomed to a life of forever travelling abroad and to be able to afford it!"