Water is imperative for all human beings and other lives on the earth. While access to safe drinking water is recognized as a part of human rights, there are a lot of people who have challenges in ensuring safe water in the world. The lack of safe water exercises a negative impact on health by causing diarrhea diseases which is one of the most serious killer diseases of under-five children in developing countries. In addition to health, a lot of studies point out that toward poverty reduction, improvement of the access to safe water is a critical agenda. Furthermore, the challenges in gaining safe water negatively impact the education opportunities of children in developing countries. Various studies point out that there is a significant link between the access to safe water and the school attendance of children, particularly girls. In terms of access to safe water, its impact on livelihoods must not be ignored. In providing safe water in developing countries, affordable and sustainable technologies, in other words appropriate technologies, should be used while sustainability of the service is crucial. In this way, access to safe water in developing countries, rural areas in particular, remains a challenge and the sustainable service model is needed based on the appropriate technology which is suitable for the local context. Therefore, this study discussed the impact and the sustainability of the water supply service in rural areas of Bagamoyo, Tanzania, operated by a Japanese small-medium enterprise, “Poly-Glu Social Business.” The company installed a water plant using affordable water flocculants and recruited the plant staff from the local community. The multi-sectoral studies were conducted by assessing the health, livelihood, and education impacts by comparing the intervention and control villages in the study areas. As a result, this study found a positive impact on health, livelihood, and education in the intervention village such as the reduction of the water-related diseases, reduction of the time for water fetching by the school children, and allocating the spare time for livelihood activities instead of using the time for the water fetching. On the other hand, this study also found that the inequality in the availability of the water services in the intervention village is due to the long distance from the water plant. For further expansion of the water services and the service sustainability, this study pointed out the collaboration of the local education hubs for entrepreneurship.
