In developing countries, poor people have suffered the most from shortages of clean water. There are several reasons for this. First, in many developing countries, the majority of houses in poor villages and urban slums are not yet served by
a piped water system. People living in these places often have to walk many miles to find water and carry it home in jugs and plastic containers. Second, these people usually have few alternatives to the piped water supply. There may be water closer by in rivers or lakes, but this is often dangerously polluted. In some areas, street vendors sell water by the liter, but they often charge extremely high prices for water that is not always safe to drink.