See Where Access to Clean Water Is Getting Better and Worse

By Nicole Washington

Around the world, 663 million people don't have access to clean drinking water. That's about nine percent of the world's population.

The reasons for this range from lack of plumbing as with tropical villages built into mountains to escape heat to the sheer distance many people live from reliable water sources. Further, shifts in the weather some thought to be related to climate change have brought droughts in some areas and flooding in others: Natural disasters like this can wreck the water table.

The numbers aren't as bad as they once were, though. In 2000, the United Nations set out to halve the number of people without access to water sources that are protected from contamination, called “improved water.” It met the target in 2010. 

Read more: http://news.nationalgeographic.com/2016/03/160301-global-potable-water-access-graphic-data-points/