Looks like unsafe dominates safe to me, by far. In the America’s, only Canada and the USA have potable water. In Asia, it’s only South Korea, Japan, and the rich city states (HK, Singapore, Brunei). In Africa, nothing, in the Middle East, just Israel.
Europe is the exception, but then it’s mostly just the EU countries. Serbia and Croatia aren’t listed as having safe drinking water (I assume it’s the pipes that are of concern, not source, like first tier Chinese cities).
Serbia and Croatia are probably just not listed due to lack of data or something. I drink the tap water there and so do locals. It's fine, never got sick.
> Serbia and Croatia aren’t listed as having safe drinking water (I assume it’s the pipes that are of concern, not source, like first tier Chinese cities).
Croatian here. It's not the pipes, it's just nonsense. Tap water is perfectly drinkable in Croatia and, as far as I'm aware, of great quality.
I've also traveled and stayed in Hungary, Romania and Bulgaria (in addition to already mentioned Serbia, Bosnia & Herzegovina and Montenegro) and no one mentioned anything about not drinking tap water.
The link you provided seems to be very unreliable source of information.
They are based on information from the CDC. If you have better maps that you use for your travels, please link. Not that I travel at all in eastern/south Eastern Europe, so “don’t drink the water unless in developed country” works well enough for me (I mostly travel in Asia outside the USA).
> Food and water standards in Croatia are similar to those in the United States. Most travelers do not need to take special food or water precautions beyond what they normally do at home.
Drank tap water in Slovakia, Hungary, Romania, Bulgaria, Croatia, Turkey, China, Egypt, Sri Lanka even the US and I am still here. I think it's more that you can't automatically assume if it comes out of tap it's safe. I was in Bulgaria this year and looked into it: there were like three villages with not safe water in the whole country. A lot better than the lead problem in the US. Ask people around, google and smell the water. It's probably fine.
A lot of places in Spain have safe water, but it often tastes so chlorinated you don't want to. When I was living there earlier this year, even after showering in the morning it smelt like I'd been to a swimming pool. I guess it's better than a high chance of getting sick if you have to drink the tap water though...
Do you have a source for "most countries"?