Drinking polluted water can cause many deadly diseases, especially in children of poor countries around the world. We see the crystal-clear water in a flowing Peruvian rainforest river but are amazed to learn that it is unsafe, due to runoff entering the great connected network of tributaries that flow into the Amazon, the world's largest source of fresh water. We learn how student fundraisers and field scientists from the U.S. have helped indigenous peoples develop water treatment systems, using their own technologies.
