I have hunted, fished, and hiked around Colorado for 15 years off and on and I have never used any kind of water purification system for my drinking water. In fact at our elk hunting camp there is a small creek fed from a natural spring about 500 feet in elevation above our camp. It runs about 10 yards from our "fire place" whick is where all of our water comes from while elk hunting. None of us in our hunting camp have ever gotten sick (4 - 6 people per year).

Up in the high country where few humans travel the water is plenty pure enough. I really don't think that a purification straw can get it any cleaner than miles of unpoluted water shed.