i dont think you should if havent been doing it for your whole life i personally have been doing it since i was a kid just make sure nothing dead is around of course
Too true. Not to mention other forms of pollution. One of my favourite BOLs is near some old Antimony mines in the hills. I would not drink from there without purification under any circumstances. So you should also try to get to know the areas where you might need to use the gound water.Flowing or not has nothing to do with it. It depends on what is up stream. High mountain streams that have little chance of beaver dams or heavy animal fecal mater are safe, anything down stream of any human or large animal activity is not.
Drank run-off from the Athabasca Glacier in Alberta - no ill effect.