Children standing at a water container on which a message is written explaining how to clean water by using the SODIS method. This project was financed by Irish Aid. It's goal is to provide clean water and a better hygiene and sanitation to the population of Nairobi's second biggest slum Mukuru-Kayaba. Solar water disinfection, also known as SODIS is a method of disinfecting water using only sunlight and plastic PET bottles. SODIS is a free and effective method for decentralized water treatment, usually applied at the household level and is recommended by the World Health Organization as a viable method for household water treatment and safe storage.