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Water Purification

Under serious disaster conditions, no water can be presumed safe for consumption. Typhoid fever, dysentery, and infectious hepatitis are diseases that are associated with unsafe water. It is important to keep in mind that water purification techniques may be effective in removing some, but not all contaminants from water. The only way to guarantee a safe water supply is to store it away prior to a disaster.

Routinely inspect a stocked water supply, this should be done at least every six months. Check containers for leaks or problems. To increase the shelf life of stored water use translucent containers, group the containers together in dark plastic bags and store them in a dark area. Polyethylene plastics including water and milk cartons can be permeated by hydrocarbon vapors and should not be stored near gasoline, kerosene, pesticides, or similar substances.

The shelf life of water depends on the original quality of the water, the temperature at which the water is stored, and how much light it is exposed to during storage. Many manufacturers of bottled water will include a shelf life on their product. Stored water may eventually develop a disagreeable appearance, taste, or odor.

Unfortunately when a crisis occurs, untainted water is not always available. A number of options exist to purify water. Boiling is one of the more popular and well known methods. Boiling water removes bacteria. In order to purify water using heat, bring the water to a rolling boil for at least one full minute (10 minutes is suggested). Cool the water and pour it back and forth between two clean containers, this will improve its taste.

Another alternative to purify polluted water, is to strain the water through paper towels, paper coffee filters, or several layers of clean cloth. This will remove any sediment or flaking material and help filter impurities. It is suggested that the water should then be boiled. Water should be boiled longer at higher elevations.

Another method of purification is to strain the water as described above, and then to chemically purify it by adding liquid bleach or tincture of iodine. To purify using bleach add 16 drops (1/8 teaspoon) of liquid chlorine bleach per gallon of water. Stir the bleach into the water. Sodium hypochlorite of 5.25% to 6% should be the only active ingredient in the bleach. There should not be any added soap or fragrances. A major bleach manufacturer has also added Sodium Hydroxide as an active ingredient, which they state does not pose a health risk for water treatment. Let the water stand for a minimum of 30 minutes. After standing for 30 minutes if it smells of chlorine consider it safe to drink. If it does not smell of chlorine, add 16 more drops (1/8 teaspoon) of chlorine bleach per gallon of water, let the mixture stand for another 30 minutes, and smell it again. If it smells of chlorine, you can use it. If it does not smell of chlorine, discard it and find another source of water. Water that is chemically purified should only be used for hygiene purposes only. If chemically purified water is consumed, it may cause diarrhea due to chlorine content and can even cause permanent kidney damage.

Do not use granular forms of household bleach to purify water, as granular bleach is poisonous. If you are using tincture of iodine to purify water use three drops of tincture of iodine per liter of clear water. If the water is cloudy, then these amounts should be doubled. An eye dropper should be stored with emergency supplies.

Liquid bleach loses strength over time. For this reason, mark each bleach container with the current date. If the bleach is one-year-old, double the amount. Two-year-old bleach should not be used.

Another alternative for water purification is to use water purification tablets. Generally water purification tablets will purify one liter of water. The tablets have a shelf life of two years and lose their effectiveness if them get damp. When purifying water only purify enough water to last a 48 hours. Water allowed to sit for longer than this may become re-contaminated.

About the Author
Francesca Black is a prolific writer and has generated a number of educational articles about emergencies. Additional articles can be found at Prepare for Emergency .



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