Water. It’s essential for survival of all forms of life. It covers 71% of the earth and yet it’s not always available – especially in an emergency. In my last post we reviewed water storage ideas. Now we’ll address the equally important topic of purifying and filtering water.
Apart from tasting bad, contaminated water can have microorganisms that cause diseases such as dysentery, cholera, hepatitis, and typhoid. Purify all water of questionable condition before drinking it, preparing food or using for personal hygiene.
Pre-Storage Purification
Before you store water for long periods of time, treat it with a preservative like chlorine bleach to prevent the growth of microorganisms. Use household bleach with 5.25 percent sodium hypochlorite, not bleach with perfumes or added cleaners.
- Add four drops of bleach per quart of water and stir.
- Seal your containers tightly.
- Label them “purified with chlorine” and include the date.
Pre-Consumption Purification
You can purify water a few different ways, but none are perfect. It’s best to use a combination of methods. Either way, if the water looks murky, filter it first before purifying.
- Let the water sit untouched to allow suspended particles to settle.
- Filter the water through layers of clean paper, cotton towels, or coffee filters.
The following purification methods will kill microbes but will not remove heavy metals, chemicals or radioactive fallout.
Purification by Boiling
Boiling is the safest method of purifying water.
- Pour the water in a clean pan or cooking container.
- Bring it to a rolling boil and continue boiling for 10 more minutes (some water will evaporate).
- Cover the water while it cools before use.
Boiled water can taste flat. To improve the flavor, shake or pour back and forth between two clean containers.
Purification by Chlorination
Liquid household chlorine bleach can also purify and kill microorganisms. Add 2 drops of bleach per quart of water (four drops if it’s extra murky), mix well and let it stand for 30 minutes. The water should have a slight taste and smell of chlorine. If it doesn’t, add another dose and let it stand another 15 minutes before testing.
Keep in mind, chlorination will not kill parasites like Giardia. Parasites can cause severe health problems, particularly for those with existing medical conditions. Boiling is the best choice of treatment for parasite contamination.
Purification Tablets
If you prepare in advance, tablets of chlorine and iodine are inexpensive and very effective. Follow the directions on the package and double the dosage for extra murky water.
Comprehensive Purification by Distillation
Distillation will remove contaminants that the prior methods are unable to remove, such as microbes, salts, heavy metals, some chemicals, and radioactive fallout (dust and dirt). In short, distillation requires boiling water and collecting the vapor. The vapor then condenses into water without the impurities.
- Use a clean pot with a lid that will stay in place when placed upside down on the pot.
- Fill the pot about halfway with water. Tie a clean cup to the handle on the lid, so that the cup will be suspended right side up when the lid is placed upside down on the pot. The cup should hang suspended above and not touch the water.
- Boil the water for about 20 minutes. The water that drips from the lid and collects in the cup is distilled.