Yah, exclusively. Wells (stagnant water, whether above or under-ground) are problematic because they tend to breed bacteria, but any out-flowing ground-spring is probably fine. Deep wells, such as aquifers, are alse safe, I think, but you're unlively to encounter accessible ones of those in the wild.

I'm suspicious of even mountain springs, although they can be utterly delicious and safe; my issue is nhen you don't know what's upstream. There are lots of farmers in the Alps who let their sheep, goats, and cattle forage in the mountains. Which is perfectly fine, except that they poop, and that gets into running water, often after having sat out and having had plenty of time to build up bacterial populations, hosting parasitic worms and such. People also contribute, but less so. I'm not worried about drinking someone else's diluted pee, which is sterile in any case.

But, yeah, ground springs are fine, and those are far more common in the Alps than most of the ranges in North America.

Of course. It's animals - including human ones - that introduce the parasites. No animals, no problem!

Stuff coming directy out of the ground is probably safe. I'd still avoid streams and rivers.

That's a great story, and it sounds like an amazing trip.

It's not a "will", it's a "might". It's a game of Russian roulette; 5 times you might be fine, but is it worth it if the 6th isn't, and you spend the rest of the vacation puking and crapping your guts out?

For me, the question is: are there any such parisites in the Alps? Maybe not. Giardia in the new world is spread largely by beavers, as I understand it, and those don't exist (much) anymore in Europe.

I wish you'd shared this anecdote sooner. Think of all the money that could have been saved on water treatment if people had only known that one time you drank from a semi questionable water source and didn't get sick.