As the sharing is takes place, have one student record the sources of pollution. Using the list of pollution sources created by the class as a guide, ask your students why each of these items contributes to water pollution problems. Label each item on the list as either point source pollution, or non-point source pollution. List 3 reasons why it may be acceptable to have any pollution enter the watershed from businesses. All the water on the earth is part of a closed cycle.
Water falls to the earth as snow or rain.
Some of the water may filter into the ground, animals or plants consume some of it, and some is stored in rivers, lakes or other bodies of water. We tend to think of this cycle as a big circle, but in reality, it is more like a web. Some of the water filters into the ground and is stored for long periods of time, some of it is frozen, while some of it evaporates. The point is that we only have a finite amount of water and we need to take care of it and not pollute it. Eventually, whatever we add to the water will end up in our water supply.