The U.S. Army Field Manual states that a human can only survive without water for three to five days. Although there may often be an abundance of water, it must be purified before you can drink it, because it can contain bacteria and parasites that are harmful when ingested. While there are several ways to purify water, the method you choose will depend on your resources.
Fill a pot approximately three-fourths full with water.
Heat your pot until the water comes to a rolling boil. A rolling boil is achieved when bubbles are rising to the surface in all areas of the pot, not just the middle.
Allow the water to boil for one minute.
Let the water cool before you drink it.
Locate household bleach labelled between five and six per cent chlorine. The bleach cannot contain dyes or perfumes.
Place your water in a clean container.
Add three drops of bleach to every one litre of water if the water is clear. Add five drops per litre if the water is cloudy or stagnant.
Allow the mixture to sit at least 30 minutes. Allow one hour if the mixture is cloudy or stagnant.
Locate a two per cent tincture of iodine. Tincture simply means extract. The percentage will be marked on the label.
Place the water in a clean container.
Add five drops of iodine per quart of water if the water is clear. Add ten drops if the water is cold or cloudy.
Let the mixture sit for 30 minutes if it is clear. Let it sit for an hour if it is cloudy or stagnant.