In 2005 there is the biggest problem for people because of tsunami which has happen that time. This problem consists in fear of outbreak of this tsunami. It can infect water with a lot of diseases and in the result it can be catastrophe because of epidemic. So providing clean drinking water has always been a major challenge in a country strapped for resources. And there is very close to water-borne diseases such as Hepatitis A, cholera, malaria, dengue and typhoid. However, hope holds out in the form of cheap and practical ways to purify available water.

This the cheapest and practical way has found. It is a Solar Water Disinfection or SODIS. Solar Water Disinfection is one such method that is already in use across 20 countries and even received a special award at the Energy Globe Awards 2004. Solar Water Disinfection particularly is very useful thing in villages where there are no proper water treatment systems.

According in developing in 1991 SODIS is a simple and very low-cost technology. It has a big potential in the nearest future. It is a panacea not only from tsunami, but it is also for a third of the population in developing countries that still has no access to safe drinking water. Because numbers of fatal outcome because of diarrhoeal dehydration are really high.

SODIS harnesses the ultraviolet rays in sunlight to inactivate pathogens in drinking water. For water above 50 degrees Celsius, the process is three times faster. However, despite proven benefits, the main problem, according to experts, is convincing people about the effectiveness of such a simple method.

To dispel skepticism about the SODIS technique, bacteriological tests of faecal coliform (FC) were undertaken. The near-zero FC content in SODIS water spoke for itself.