Session 3: Pollution in Your Water

How does pollution get into your tap water?
Water moves across the land picking up materials in its path. If the land is polluted, the water will be polluted too. No matter where you live, water pollution can be a serious problem. Water pollution is bad for the environment and bad for your health. Nitrate, a water pollutant, is one of the fastest growing causes of pollution in this country.

Try This!  

1 Pollution in the Land = Pollution in the Water
2 Finding the Source
3 Sources of Pollution
4 Quiz Yourself

1 Pollution in the Land = Pollution in the Water Top

Read to Learn:
When we pollute the land, we also pollute the water. As you saw in the watershed model activity (Session 2), pollution on land can enter streams, lakes, and rivers as water moves through the watershed. These streams, lakes, and rivers may be the source of your drinking water. By learning about pollution, you can make choices that help keep your drinking water clean.

Do to Learn: Classroom
Draw a polluted picture.

Think back to your model watershed and what you learned about your own watershed. Draw a picture of your watershed, showing how the water flows from hills down into the stream, lake, or reservoir that brings water to your school. In your picture, add a few examples of things that could pollute your water. Share your drawings with the class.

2 Finding the Source Top

Read to Learn
By now you know a watershed is the land that water passes through before it gets to a stream, river, lake, or ocean. When you investigated the watershed model, you may have seen that some of the water traveled down one side of a hill, while the rest of it traveled down the other side. In the real world, the tops of hills are called ridges or divides, and they split up different watersheds. All the water flowing down one side of the hill is in one watershed, and all the water flowing down the other side of the hill is in a different watershed.

Do to Learn: Computer Lab
Find your very own watershed.

In this activity, you will find out more about where your school’s tap water comes from. The land is divided into many different watersheds, and this is your chance to find out which watershed is yours. After you find your school’s watershed, you can investigate how clean it is. Before you begin this activity, your teacher will tell you what stream, river, lake, or reservoir your school’s water comes from.

Locate your watershed at

  1. Open the link.
  2. Click on your state.
  3. Click on a place that is closest to the location of the water source for your school.
  4. Be patient, and two watershed maps will appear.
  5. Examine these maps and think about the following questions:
  • How big is your watershed?
  • Have you ever been to any of the places in your watershed?
  • What kind of land is your watershed on? Are there lots of cities in your watershed? Are there factories, roads, or highways in your watershed?
  • Where might pollution in your watershed come from?
Discuss your ideas with your partner.

Extension Activity: Computer Lab
Learn more about watersheds at

3 Sources of Pollution Top

Read to Learn
As you saw in The Nitrate Story, there is usually more than one cause of pollution. It is important not to point fingers and blame one person, because pollution doesn’t usually come from a single source. Many everyday activities wash pollutants into our waters.

Residential Pollution
Many people do not realize pollution can come from their own backyards. It is often easy to spot pollution from a factory or to see that trash dumped along a stream is causing pollution. However, the neighborhoods where people live can be serious sources of pollution.

Do to Learn: Computer Lab
Take a look at this visual list of things we do wrong in the environment:

Extension Activity: Classroom
List the things you can do to prevent residential pollution.

Here are a few examples:
  • Sweep driveways and patios clean instead of hosing them down.
  • Take oil to a local recycling center or gas station that accepts used motor oil.
  • Minimize fertilizer and pesticide use on your lawn and garden or switch to organic, nontoxic alternatives.
  • Create a compost pile as a source of fertilizer to use in the garden. If lawn chemicals are used, apply only when rain is not forecast.
Can you think of more? Brainstorm as a group and write your answers down.

4 Quiz Yourself Top

Do to Learn: Classroom
Draw a pollution-prevention picture.

Draw a picture of the things you can do to prevent pollution from entering ground and surface waters in the first place.

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