Solar water disinfection is a process in which water is purified using the sun’s ultraviolet (IV) rays. The higher the temperature, the faster this process works. If it is a sunny day, the water is disinfected within 6 hours. If it is cloudy, it will take 2 full days. This system should not be used if most days are rainy.10 Solar water disinfection will kill many impurities that include bacteria and viruses, Giardia, cryptosporidia parasites and other microorganisms.

• First filter water
• Fill bottles with water, preferably clear PET (polyethyleneteraphtalate) types, that are 2 liters or less
• Shake the bottles
• Place the bottles where solar radiation can reach the bottles (directly in the sunlight)

After SODIS treatment, it is important to use the water fairly quickly. If the bottles are stored in a dark area, remaining bacteria not killed by radiation can begin to reproduce again.