Lesson 3

  The addition of any substance that has a negative effect on water or the living things that depend on the water.  Sources of pollution are classified, in part, by how they enter a body of water.  Two sources of pollution are 1. 2.

 A pipe gushing polluted water into a river is an example of a _________________________ of pollution.  A widely spread source of pollution that can’t be tied to a specific point of origin is called __________________________.

 __________________ are chemicals intended to kill insects and other organisms that damage crops.  Bathing or swimming in polluted water can irritate the skin or cause more serious problems.  If we eat contaminated fish regularly, the toxic chemicals can build up in our bodies, which can also be harmful to your health.

 The three major sources of water pollution are: __________ is a disease caused by bacteria that live in human wastes, that can be fatal.

 Wastewater is usually treated before being released into the environment.  During ____________ and _______________, sanitary sewers sometimes overflow and run into storm sewers. This can lead to polluted waters.  People often ______________ water for drinking and cooking after a flood to kill off many disease-causing organisms.

 _____________________, __________________ and ____________________ are three types of pollutants produced by factories, mines and other industries.  _________________ is rain or another form of precipitation that is more acidic than others.

 _____________ and ______________ water also carry away other pollutants from farm fields.  Gasoline, oil, and salt are __________________ sources that pollute rivers and lakes.

 Solving pollution problems involves cleaning up exiting problems as well as preventing new ones.

 Many pollutants are removed from fresh water through natural cleanup processes.  _______________________ bacteria can also prove to be useful in breaking down toxic chemicals in rivers and lakes.

 Many industries have found that ___________________________ techniques that conserve water also reduce pollution.

 What can the government do to clean up water pollution and to help prevent it?  Why should drinking water and sewage be kept separate?  How can pesticides pollute water?  What are three types of industrial pollutants?