This next topic is vitally important to understand. Water that has been contaminated with radiation particles, dirt, bacteria or other pollutants requires purification that basically takes a 2 step process. First step is to clean the water of all physical impurities such as dirt and debris. Then it must be made biologically safe to drink. These are some of the methods you can use to remove physical pollutants
1. Settling: To clear muddy water let it stand for 12 to 24 hours. This will allow any sediment to sink to the bottom of the container (due to gravity). A handful of clay soil in each gallon of water will help this settling process.
2. Siphoning: This process will eliminate most particles and silt from the water. Elevate the polluted water above another container and run a piece of brained yarn, string of cloth, string or hose with a piece of cotton or cloth in it as a filter. If yarn or string is used, it helps to soak them in water first to get the process started. Dirt and debris will not be soaked up, but will remain in the top container.
3. Straining: This is the fastest way of eliminating physical pollutants from water, but be sure that your straining material is fine enough to trap the sediment or you may have issues. Use piece of cloth, paper towel or even layers of grass and charcoal.
Once the physical pollutants have been removed the job is only half done. These physical pollutants, though unpleasant to the taste, are usually quite harmless. The important task is now to make the water safe to drink by eliminating or killing the microbiological pollutants. These will be discussed in Water purification Step 2.