How to Make Rain Water Drinkable

Rainwater is drinkable when appropriate precautions are taken.

The consensus of scientists at the U.S. Department of Energy is that rainwater is drinkable as long as it has not come into contact with anything. However, for safety, further steps can be taken to purify the water.

Things You'll Need

• Food-grade container
• Sand
• Sterilized, air-tight container
• Chemical filtration device

Instructions

1. Position food-grade barrels or other containers in an area where they will catch rain directly from the sky, and not via the roof, trees or plants. Plastic barrels with taps are fairly cheap and simplify the process of getting the water out of the barrel.

2. Place netting or wire mesh over the tops of the containers to prevent leaves and other objects from falling in, which may contaminate the water. Because dust, bird droppings and other contaminants may still enter, a purification method should be used. There are several options.

3. Filter the water using a chemical purifier, available from most outdoors stores or online.

4. Filter the water using a home-made sand filter, also known as a biofilter. Because sand filters are typically larger than chemical filters available from stores, they are a more practical choice.

5. Boil the water after filtration, to ensure that harmful micro-organisms have been killed. According to Rick Curtis, author of The Backpacker's Field Manual," all harmful pathogens will be killed by the time water reaches boiling point. However, leaving the water to boil for one minute is a sensible precaution.

6. Store the water in sterilized, air-tight containers. According to the International Bottled Water Association, bottled water can be stored indefinitely if kept in a cool, dry place away from direct sunlight.

Tips & Warnings

• People living in polluted areas should wait some time after the rain begins to allow pollutants to be washed out of the air.

• Do not drink discolored water, or water with an unpleasant odor.

References

• US Department of Energy: Drinking Rain Water
• "The Backpacker's Field Manual"; Rick Curtis; 1999
• BottledWater.org: Frequently Asked Questions

Resources

• ChelseaGreen.com: Project: Harvest Rainwater with Sand Filters
• BioSandFilter.org