NOTE: You should read a lot more about this subject before drinking water from an unknown source using this technique. I employ the use of boiling and purification tablets when possible in addition to this.
Water is without a doubt the most important thing you will need in a survival situation. There are MANY ways to handle filtering your water for drinking. Remember, filtering and purifying are NOT the same thing. Here’s what you will need:
• Two 5 gallon buckets
• One spigot (on/off capable)
• Mesh Screen (door screen will work)
• Tools to cut your buckets
Label your buckets as follows: RAW WATER and FILTERED WATER
Wash all materials, including charcoal and gravel, before building the filter system.
FILTERED WATER BUCKET – Take the Spigot and install it approximately 1/2 inch above the bucket’s bottom rim.
RAW WATER BUCKET –
• Cut 5 holes in the bottom of this bucket. Each hole should be about 2 inches in diameter.
• Cut two pieces of screen mesh to fit inside the bucket and place them on the bottom.
• Pour about 3 inches of course sand into the bottom of the bucket. Level it out and ensure it is not leaking through the mesh. If it is leaking through, remove all materials and add another mesh layer. Repeat adding mesh layers until sand does not leak.
• Pour water into the bucket to ensure that it comes all the way through the holes in the bottom.
• Add a 3 inch thick layer of finely crushed charcoal on top of the sand. Test water flow.
• Add a 3 inch layer of crushed gravel on top of the charcoal. Test water flow.
• Place a single layer of mesh on top of the gravel and then repeat the layers of sand, charcoal and gravel again, testing for water throughput each time.
When the bucket is completed you will place the RAW WATER bucket on top of the FILTERED WATER bucket. Place the buckets in an area where you can access both the top of the bucket set and the spigot at the bottom without issue.
Pour raw water into the top bucket and it will filter as it makes its way through the different material layers. The process should take a few moments as the filtering materials slow the speed of the water. Once the water is in the lower bucket, you can use the spigot to extract the water from the system.
NOTE: You will STILL need to purify the water through other means. Filtering only removes the large objects in the water it does not clean the water of bacteria, virus or anything else. I suggest boiling all water that comes from a homemade filtering system. Also, the water may or may not be clear. Get used to drinking stuff that doesn’t look tasty. Clean your materials and change out your filtering medium weekly if possible.
NOTE: Replacing the wire mesh with some form of cheesecloth would be fantastic if you have it available. I only use wire mesh in my examples because it is readily available in most cases.
You can purchase a pre-built system similar to this at: http://emergency-h2o.com/filter-systems-5.0-gal-18.925-liters-deluxe-system.html
If you are truly living off the land, you are just going to have to take your chances. Try to find a water source that is not stagnant. Flowing water is likely to be much cleaner than stagnant water. If you can locate the water at its source, you may be able to reasonably assume its purity or cleanliness.