Clean water is essential to our health and functioning. Most of the time we take having access to pure water for granted: water filters at home/work/school, or being able to purchase bottles or jugs of water from the store. In situations where the water is questionable (containing parasites or bacteria) it is possible to purify water yourself to make it more fit for consumption. For example, if you are in the wild, amidst a natural disaster, or live in an area where water isn’t purified for you, follow these steps to ensure safe water:
1. Make sure your water container is clean. Use soap and water to clean thoroughly. Once the container is washed, submerge it in a solution of 1 teaspoon of household chlorine bleach to every liter of water. Finish up with a rinse of a weaker mixture of bleach and water.
2. Filter water through a clean cloth. Afterwards, let it to settle for at least 30 minutes and pour off the clear water for purifying.
3. Speed up the clearing of water. Add a little aluminum sulfate which causes impurities to thicken, and can then be removed as the particles settle to the bottom of the container.
4. Purify the water. If possible, combine boiling with a chemical disinfection method
- Boiling: This is the preferable purification technique as it kills most bacteria and microorganisms. Boil the water for 1 full minute (4 minutes if more than one mile above sea level), then let it cool.
- Disinfecting: Add 1/8 teaspoon (8 drops) of regular, unscented, liquid household bleach for each gallon of water. Stir well and let stand for 30 minutes before you use it.
- Granular calcium hypochlorite: Dissolve one heaping teaspoon of high-test granular calcium hypochlorite in two gallons of water to make a disinfecting solution. Then add one part of the disinfecting solution to each 100 parts of water to purify.
- Potassium permanganate (KMnO4): This is an emergency purification measure only. It can be purchased from camping supply stores and pool treatment stores. Follow directions on package.
- Disinfecting with iodine: Add 5 drops of 2 percent iodine (from the medicine chest or first aid kit) to every quart or liter of clear water; add 10 drops if the water is cloudy. Let the solution stand for at least 30 minutes.
- Commercial tablets: For commercially prepared chlorine or iodine tablets, follow the instructions that come with them.
- Solar water disinfection method: Pour the water into clear plastic PET bottles, and put in direct sunlight for at least 6 hours. This has been shown to be an effective method of disinfecting.
5. Be mindful of the cap or lid of the container. If container has a screw-on cap, wait about five minutes after adding the purifying chemical(s). Slosh some water on the inside of the cap and the threads of the container, then re-tighten the cap and let it sit for the remainder of the time specified.
6. Improve the flavor of purified water, if needed. Aerate water by pouring it from one clean container to another several times. Or add a pinch of salt to each quart or liter of water.
7. Use proper consumption techniques. Don’t touch the inside or the rim with your fingers. If you’re going to drink some (not all of the water) don’t drink directly from the container — pour it into another container and drink from that.