The world uses about a thousand million (百万) tons of water a day. Water is a human right and everyone should have their share. Yet more than 700 million people around the world have trouble getting clean, safe water.Treating wastewater is a good way to provide fresh water for us. And it also helps the environment by keeping waste out of rivers and oceans. 80% of wastewater around the world is not treated at all, and it is running into oceans. But now we have got the technology to treat and reuse the wastewater.While 75% of our planet is covered with water, only about 2% is fresh water—th