Why do so many people going /out/ seem to have such fear of natural water sources? Where exactly are people going outdoors where the water isn't clean? This may be some hippy nonsense but I feel like if you're actually in nature (and not, say, in a city park) then any running water you can find will be way cleaner than anything that comes out of a tap. Even the official site of the forest service is telling me to STAY THE FUCK AWAY from natural water sources without. What is going on here? Are they in the pockets of Nestle and backpacking water filter companies? Or is there actually risk to drinking from natural water sources that I've somehow avoided for my 20+ years of doing just that? I mean, obviously, you don't drink from a pond with algae growing on it, unless you are desperate. But outside this how much risk could there be?