That's a good point, I think it very much depends on the area you are in, that's why I added sub-pages for each country, e.g. https://www.iswatersafetodrink.in/germany/Munich. Although to be fair they are still lacking serious data, I'm working on that!

Someone in the chat was kind enough to provide me a good water quality source for Hamburg, if anyone is interested here is the link: https://www.hamburg.com/residents/housing/12792124/water-qua...