Designing a Walter Filtration Device

Designing a Walter Filtration Device

Of all the elements of survival, water is one of the most important things to consider.  Depending on your resources, there are several different ways to purify water.  One of the easiest ways to collect water from your surroundings is to place a discarded plastic bag around a branch of a plant.  This will not only able you to collect morning dew, it will also allow you to collect water throughout the day.  As the sun heats up the plant, it evaporates water.  The water is then trapped in the bag.  The benefits of this method is its ease in setting up and taking down.  The drawbacks are the quantity of water this allows you to collect.  This is a good idea for short term water use, but will not be sustainable over a long period of time.    

Another device that is relatively easy to set up is a natural filtration system.  As the picture below indicates, it consists of three layers of material.  It is best to repeat these layers multiple times.  If the charcoal that is being used is activated charcoal (see my article on activating charcoal), then it is much more effective.  This system will purify water as long as the water is not highly or very contaminated.  The benefits of this system is that it is easy to set up and use.  The drawbacks is that if your water is pretty dirty to begin with, it may not eliminate all of the contaminates.  

Creating a solar still is a good option for long term water purification.  There are many different designs out there, but they all consist of similar principles.  It essentially traps evaporated water and collects it.  This is similar to the first idea, but it involves a more permanent setup.  The solar still will eliminate almost all contaminates.  The drawbacks are in the time amount of time it takes to get a good quantity of water.  Another more simple method is to take a bottle of water and leave it in the sun.  There is no real science to this, but the sun will eventually kill all of the harmful bacteria inside.  Since this is not a exact method, it should be seen as a last resort.    

Another way to purify water is chemically.  Two chemicals that are readable accessible are bleach and iodine.  If your water is cloudy, funnel it through a cloth or filter.  If you do not have a filter, then wait until the water settles and then scrape the clean water off the top.  For iodine, place 5 to 10 drops per 32 fluid ounces or 1 liter (the amount of drops depends on how clear the water appears).  Be sure to use iodine that has a 2 percent tincture.  Let water stand for 30 minutes before drinking.

Chlorine is another great way to purify water chemically.  There are many different thoughts on how much chlorine is needed, but according to the EPA, 8 to 16 drops or 1/8 to 1/4 teaspoon, should do the trick.  Like iodine, let the water sit for 30 minutes before drinking.  The chlorine smell in the water should disappear after a few days, but it is harmless.  One great thing to keep on hand is pool shock.  This is sold at most stores as pool supplies.  It is essentially chlorine in concentrate.  With just a bucket of this, you can make hundreds of gallons of chlorine, and consequently, you can treat thousands of gallons of water.  

  

Boiling water is always a good way to purify. It is best to boil water for 1 minute at sea level, adding 1 minute for each additional 300 meters above sea level.  Or boil for 10 minutes no matter where you are.  Make sure the water is boiling before you start counting the time.  There are a lot of websites that insist that water should be boiled longer and, although it will not do any harm, it is not necessary.  This is the safest method but comes with its own drawbacks, such as needing a constant heat source.