I got my first filter about 15 years ago. For the 55 years prior to that I drank it like I found it. The body has it's own immune system and, if healthy, builds against repeated incursions by harmful pathogens. However, I lived and played in areas upstream from Industry and the masses of humans. ( Rule #1, drink upsteam from the herd.) As far as I know, all my bellyaches and other gastrointestinal malfunctions during that time was attributed to other than water borne critters.
Anytime a person changes their excercise, diet, and sleeping patterns they can expect intestinal changes as well. Backpacker Mag did a study on filtration. It was an excellent read and one I wish I could find and reread. One of their studies involved setting up a question kiosk where people were coming off the AT. The questions were worded in such a manner that of the 200 plus people interviewed, after completing the questions 71 were convinced they had Ghiardia. But only 1 had been out past the 96 hour incubation period.
All that being said, I now filter most everything just to be sure. But I still have a nice long sip of natural water when I run across a spring or fast moving small brook. But back to the original question, we are not talking drinking natural water while wandering the mountains. As a prepper concerned with water supplies during a long crisis, you can expect all types of contaminations, from petro chemicals to human waste and even the possibility of radiation in the waters. No one system is going to provide safe water in that environment. I don't have all the answers to that dilemna. I can only worry about what I may have to deal with in my area.
Anytime a person changes their excercise, diet, and sleeping patterns they can expect intestinal changes as well. Backpacker Mag did a study on filtration. It was an excellent read and one I wish I could find and reread. One of their studies involved setting up a question kiosk where people were coming off the AT. The questions were worded in such a manner that of the 200 plus people interviewed, after completing the questions 71 were convinced they had Ghiardia. But only 1 had been out past the 96 hour incubation period.
All that being said, I now filter most everything just to be sure. But I still have a nice long sip of natural water when I run across a spring or fast moving small brook. But back to the original question, we are not talking drinking natural water while wandering the mountains. As a prepper concerned with water supplies during a long crisis, you can expect all types of contaminations, from petro chemicals to human waste and even the possibility of radiation in the waters. No one system is going to provide safe water in that environment. I don't have all the answers to that dilemna. I can only worry about what I may have to deal with in my area.