In an extended primitive survival situation or wilderness living, one of the most reliable and efficient ways to procure safe water in large quantities is simply to dig a primitive well or coyote well. People have been using hand dug wells for thousands of years and, if done right, they’re a fantastic source of pure, clean water. The earth itself acts as a primitive water filter. To dig a proper well is a lot of work. But, for a long term wilderness living where potable water isn’t readily available, it’s well worth it. Humans lived for a hundred thousand years without processing water. It’s only in the last few decades or so that we’ve come to believe that raw water is unsafe.