You won't last 3 to 4 days without water. It's very important to consider any water you find out in the wilderness to be contaminated. You need to filter out everything you can then boil it for at least 5 minutes. Here's how to make a field expedient water filter.
- Find an empty plastic water bottle. Not hard, you probably have one in your pack, and if not, look around, there’s probably one nearby. Humanity's trash gets everywhere.
- Carefully cut the bottom half inch off the bottle and punch several small holes in the plastic water bottle lid and screw it back on tight.
- Gather some of the black charcoal from your last fire (You don’t want the gray ash) , or make some, by packing and tightly containing wood in a steel can (like a paint can) and punch a few small holes in the lid. Build a fire around that can and let it burn, good and hot, till the smoke stops coming out of those holes. Allow the can to cool completely. Break down almost all of that charcoal to as small a pieces as you can get it. Pound and grind it between rocks. Also keep a few small chunks and put them in your fire kit.
- Gather a handful of acorn to walnut sized rocks, easily found along stream beds.
- Gather a handful of pea sized gravel, also found in stream beds.
- Gather a handful of coarse sand, again, stream beds.
- Gather a handful of fine sand.
- Cut a small corner of your cotton material and stuff it into the bottle neck. (NOTE: The bottle in question is inverted so the lid is the bottom of your filter, the hole where the bottom was, is now the top.
- Pour the charcoal in first so it’s closest to the lid. Tap and shake the bottle so the finer bits of charcoal are closer to the bottom. In a half liter bottle, you want about two inches of charcoal.
- Pour in the fine sand. About an inch.
- Pour in the coarse sand. About an inch.
- Pour in the pea gravel. About an inch
- Pour the acorn sized gravel. About an inch
- Create a pre-filter out of your cotton material (spare or current clothing, dew rag, bandana) to filter out the big chunks) and lay over the top of your filter.
- Place your filter over the metal container you’re going to boil it in and secure it somehow.
- Pour your unclean water through your filter, the water will slowly fall through the filter and what comes out will be “clean” water. This type of filter, if done correctly, will filter out just about all the bacteria, Parasites, Crypto-Sporidium, Giardia, and turbidity (all that junk floating around in the dirty water that makes it cloudy).
- Just to be doubly safe; boil that clean water for 5 minutes at a rolling boil because it’s always possible that something got through the filter. The last thing you need in a survival situation is dysentery, and vomiting. You’ll dehydrate quicker than you can rehydrate!
- NOTE: Unless you use the same container to collect and boil water in, If at all possible, use a separate container to collect the dirty water and never use it to drink out of.
If you can’t filter out the turbidity you can leave the water to sit and allow the gunk to settle out. Once the water is as clear as it’ll get, carefully pour it off through your cotton material into your metal container to boil it. Boil for 5 minutes at a rolling boil, allow it to cool and drink away. It won’t be Crystal Geyser, but it will be safe enough to drink. Regardless of whether you filter your water or you just let it settle out. After you boil it, it’s going to taste flat, a little like pond water, and a lot like your campfire. If it’s been a day or two since your last drink, you won’t care, the taste will be the least of your worries.
Be safe out there and always be prepared for the worst-case scenario.
