Appendix T

Making Safe Drinking Water

The first choice is to bring water treatment devices with you whenever you travel to a developing country. However, if you have forgotten to bring one, consider the following options to make safe drinking water: Boiling: Vigorously boil water for 5 minutes. The flat taste of boiled water can be improved by pouring it back and forth from one CLEAN container to another. Also, a small pinch of salt can be added to each quart of water boiled; Chlorination: Add 5-10 drops chlorine bleach per quart of clear water, thoroughly mixing it and allowed to stand for at least 30 minutes. The treated water should have a slight chlorine odour; if it doesn't, the dosage should be repeated and the water should stand for 15 minutes more. If this treated water has too strong a chlorine taste, it can be made more drinkable by allowing the water to stand exposed to the air (should be a light cover over the top to prevent insects, etc. from falling into the water). Pouring it back and forth between two CLEAN containers will also help.

As a last resort, if the above options are not available, consider the following:

UV Exposure: Make safe drinking water by putting clear water in a clean container and expose it to bright, hot sun for at least 8 hours;

pH Adjustment: Add lime to bring the pH above 10 for several hours. Expose the water to atmosphere for several hours to allow natural CO₂ reactions to bring the pH back down to at least 8.5 prior to drinking. Please note that this should only be used as a last resort since the validity of this method to make safe drinking water has not been scientifically investigated.