Many American scientists are worried about the drinking water in the United States. They think that soon there may be no more clean drinking water. Dirt, salt and chemicals from factories can get into the water. Then it is not safe to drink. This is already true in some places. One example is a small town in Massachusetts. Many children in this town became sick because of the dirty water. Another place with water problems is Sacramento, California. The water near an airport in Sacramento is not safe to drink. Many other cities and towns have water problems. too.