Water Purification Wilderness Style

Not only does the sun provide light, warmth, and vitamin C, according to research it can also purify and disinfect potentially contaminated water. This method of water purification is called “Solar Water Disinfection” or SODIS for short. The SODIS method works by use of the sun’s thermal energy, or heat, and UV radiation. The ultraviolet radiation emitted by the sun kills bacteria, parasites, and other harmful pathogens in water and, in effect, sanitizes the water. This is an extremely simple way to ensure your water is drinkable if you ever find yourself in a wilderness scenario without the access to clean water.

All you need for the SODIS method is a clean PET bottle, which is the clear, plastic bottle that most sodas and other drinks are often packaged in. Not only is using a PET bottle cost-effective, it is also proven to be safer than some variations using glass bottles, which UV rays cannot always penetrate. It’s important to ensure that the water bottle itself is as clean as possible before going through with this very easy process.

All that you need to do now is fill up the bottle about three quarters of the way, secure the lid tightly, and place the bottle in the sunlight, preferably on a reflective surface, for at least six hours. How simple is that?

A few things to keep in mind if you’re going to try out this trick on your next camping trip are that if the water is turbid, you may need to filter it before proceeding in order to make sure the solar disinfection works as it should. Also, leaving your water bottle in the sunlight for up to two days can maximize effectiveness in cloudy weather, when there is a lack of direct sunlight.

The SODIS method is tried and true, and both UNICEF and The Red Cross have even proposed this method for use in developing countries where clean water is a scarce commodity.

– Shreya Wadkar