As I stated in Part 2 of this series, the presence of perennial water is what's most important in selecting a home territory. Cleanliness is not so much a concern as long as it is not chemically contaminated or has heavy mineral content. Water can generally be filtered and sterilized even without modern filtration methods. It is a good idea though to bring a several methods of making save drinking water with you as you get established.
I do not like chemical sterilizers such as chlorine or iodine, as these will damage your gut bacteria and weaken your immune system. There are natural agents that you can use instead such as citricidal and colloidal silver. Most environments have herbs that will kill harmful bacteria and parasites and a tea can be drunk of these such as Algerita, Horehound, Crucifixion Thorn and many others. It is up to you to look up what grows in your area.
Microfilters are very handy, ceramic ones being the best in my opinion. I carry several different types. In my sporran I have a small filter about the size of a roll of quarters that attaches to about 3' (1m) of aquarium tubing that I use to drink directly from creeks, springs and the like. I have a Life Straw in my pack as well.
One of these days I'd like to get my hands on a couple Grayl canteens and cache extra filters. They look to excellent products. It is nice to be able to drink freely and not suck water through a filter. Once you have an established permanent camp or cabin, I would not be opposed to having a large filter such as a Berkey either.
Without sterilizers or modern filters, the other option is filtering out any large particulates and then boiling to sterilize. Many times most of us carry only a small stock pot with us, perhaps 4 quarts at most, in our packs. Again, this is where cached gear comes in VERY handy. Stainless steel canteens are really the way to go. Instead of boiling your water and having to wait for it to cool, as you would with glass or plastic, you can pour it directly into your canteens and get the next batch going. You can even boil water directly in a stainless steel canteen.
There are many other methods to boil your water but the focus of this post is gear and not necessarily skills. Some of these methods include using hot rocks, various types of stills, natural filters, pottery, wooden bowls and even leaf-lined pits. If you prepared properly and cached gear, you should not have to depend on these. They are good skills to know and practice but fall more under the realm of survival techniques. The truth is that there is trash everywhere and we can almost always find a man made container to boil water in.
When I am very active, I can easily go through 5 liters of water a day, more depending on the weather. That is very hard to carry on you and you don't want to have to boil water all throughout the day and then have wait for it to cool enough to drink. Having a large pot cached is very helpful. Not only can you use it to boil your daily drinking water, but you can warm your water for bathing, rendering fat in large batches, soak hides for tanning and of course cooking large pots of food. I am VERY fond of my 28 quart pot, it sees a lot of use.
What I end up doing most of the time is boiling a large pot of water each day, letting it cool and then transferring it into old 1.5 liter glass liquor bottles. They are free and all over the place here in Appalachia. Unfortunately asshole people dump trash down in the hollows but they can be a resource for us scroungers. Anytime I run across good glass bottles and 5 gallon plastic buckets, especially when they have lids, I snatch them up. The buckets with sealed lids make for good caches.
I end up building multiple permanent structures on my home territory and I like to cache ready bottles of drinking water at each one. You never know where or when illness or injury might limit you. Another thing I like to do is put a small amount of salt in my drinking water for electrolytes, it makes a HUGE difference in your energy levels and recovery. I use either sea salt or unrefined mined salt so it has a higher mineral content. Salt is one of those incredibly important cache items. It won't spoil and you can never have too much stored.
Now we will cover fire. I think it is extremely important to have your ability to use primitive methods down and used whenever possible. Save the modern methods for when you are in a rush or an emergency situation. Become proficient in friction fire methods such as my favorite, the hand drill. Having a method that uses the fewest parts will give you a level of comfort that cannot be over stated.
The bowdrill and fire saw would be my next choices. From there work on flint and steel, then ferro rod, magnifying glass, matches and lastly, a good old Bic lighter. There are many other methods such as the pump drill, fire plow, using a battery and steel wool, all manner of ways. Learn as many as you can, YT is an excellent resource.
Caching fire starting tools throughout your home territory is always a good idea. Do not limit yourself to just the initial spark or flame though. Have tinder and dry firewood tucked away as well. Char cloth and cotton balls are some good man made materials. Natural coal catchers would be prepared tinder bundles such as cedar bark, the inner bark of Tulip Poplar, Birch bark, dry grass or pine needles and the like. Having a coal extender is helpful too such as chaga or fatwwod, dried dung also works well.
Redundancy is the best safety. Again, our goal is to succeed, not suffer. Carry and cache multiple methods of obtaining clean drinking water and creating fire. Have modern, robust methods but do not solely depend on them. Primitive methods have the greatest longevity and offer the most security. Skill over gear always. (But carry and cache a damn pot.)