The SODIS project represents Eawag’s commitment to clean drinking water in developing countries. The very simple method used was developed more than ten years ago by an interdisciplinary research team. Today, this aquatic research institute is working in three continents to propagate SODIS and thus to save lives.

The SODIS method is ideal for treatment of drinking water in developing countries. It requires only sunlight and PET bottles. The water is decanted into transparent PET bottles and left in the sun for six hours. The UV-A rays in sunlight kill pathogens such as viruses, bacteria and parasites. The method also works at low air and water temperatures. Thus, solar water disinfection offers a solution for the prevention of diarrhoea, one of the most common causes of death for people in developing countries. The SODIS method was developed in the 1990s by an interdisciplinary Eawag research team of microbiologists, virologists, engineers and drinking water specialists, based on earlier work by Lebanese researchers.

International recognition

The World Health Organisation (WHO), UNICEF and the Red Cross recommend the SODIS method for treatment of drinking water in developing countries. Already more than 5m people purify their drinking water with the SODIS method. On the other hand, it is still unfortunately the case that almost 1bn people have no clean drinking water. For this reason, Eawag has intensified its activity in recent years, during which period the number of projects in Africa in particular has increased considerably. At the same time, Eawag is supporting the further development and propagation of the SODIS method by means of research relating to microbiology, health, education strategies and PET bottles.

Projects in 24 countries

Eawag is currently running SODIS projects in 24 countries in Africa, Asia and Latin America. Competent and motivated local partner organisations implement the projects in the field. Information is provided to governments and development organisations in order to convince them that they too should commit to the provision of access to clean drinking water. As the execution of SODIS projects is not part of Eawag’s core activity (research), it relies on donations for the propagation of the SODIS method.