The UN says that each person needs between 20 and 50 liters of safe freshwater per day for drinking, cooking, and cleaning. Yet more than one in six people worldwide don’t have access to this amount—and some 2.5 billion live without access to even basic sanitation facilities. Combined, these have a shocking impact: Globally, diarrhea is the leading cause of illness and death. But the failure of international intervention has left the door open for grassroots solutions: In both Indonesia and the Philippines, a small entrepreneurial approach to safe water provision has achieved massive scale in an extremely short time span. The “water refill” industry, which utilizes low-cost technology to purify water on site in locally run businesses, has received little attention in the West, but it represents possibly the most effective means for water delivery in the developing world.Molecular biologist Ranjiv Khush and hydrologist Jeff Albert are now hoping to replicate the Asian model in other parts of the world, beginning in East Africa. Click on the image or title to learn more.