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Disaster Preparedness & Recovery Information

How do I purify water?

Boil water at a rolling boil for 10 minutes. A pinch of salt added to each quart of water improves taste. You can also purify water with two chemicals: chlorine bleach and iodine.

Chlorine bleach (unscented) such as Clorox or Purex. Check the label to be sure that hypochlorite is the only active ingredient. Do not use bleach that contains soap.

Use the following amounts:

  • 1% chlorine - Add 40 drops of bleach/ gallon of water
  • 4 to 6% chlorine - Add 8 drops of bleach/gallon of water
  • 7 to 10% chlorine - Add 4 drops of bleach /gallon of water

Mix bleach into the water and let stand for 30 minutes. Water should have a slight chlorine odor. If it doesn't, repeat the process and let the water stand for an additional 15 minutes.

Iodine. Iodine from your medicine chest can also be used to purify water. The iodine should be 2/United States Pharmocopeia(U.S.A.) Strength. Add 20 drops/gallon of clear water, and 40 drops/gallon of cloudy water.

Water purification tablets are available at drugstores. Follow manufacturer's directions.

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