I'm from in east Tennessee (in the mountains), and water supply for the neighborhood I grew up in is fed by a natural spring. I worked for the water utility in

I'm from in east Tennessee (in the mountains), and water supply for the neighborhood I grew up in is fed by a natural spring. I worked for the water utility in high school and quite often drank the water from the spring before it was treated. The treatment process was basically adding chlorine to meet government regulations. I've also consumed quite a bit of water from rivers and creeks I've been kayaking on and haven't had an issue yet. * Don't get me wrong, I'm not claiming all water is safe to drink; when I go backpacking, I take a filtration system with me. But I also don't want to get stuck somewhere with digestive tract issues.