Originally Posted By: NobodySpecial
I'm inclined to believe it's the temperature rise rather than the UV, otherwise the top 6" of every stream and lake would be sterile.


Perhaps the UV sterilized the shallow rocky potholes from which I used to drink in Arizona. I vividly recall one into which I plunged my face and drank deeply. Finally satiated, I lifted up and noticed some submerged coyote turds about one foot away. I suffered no harmful effects whatever.
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Geezer in Chief