The Backwoodsman, as a very good magazine. I have been meaning to subscribe to it. Potable water could be a real problem, and there is much to worry about if you're forced to rely on alternate sources. There is a lot of chemical, and pesticide runoff contamination that is very hard to remove. If I wanted to supplement a residential water supply, besides ground water(if it tests good), I would look at a roof water, cistern storage system.