Note: Teacher’s notes are in red.

Students will develop a definition of pollution, identify how people pollute water through nonpoint source pollution, and learn how to reduce nonpoint source pollution.

Your Mission: Make a point to prevent river pollution!

Subjects: Geography, Science

Relevant U.S. National Geography Standards: 14, 16, 18

Materials:

• Aquarium plants (e.g., Anacharis; also called Elodea densa)
• Pollutants (e.g., cooking oil, liquid soap, salt, others)
• Rubber gloves, plastic bags (for the teacher)
• Small aquariums or other clear containers

Survey Says. . .
If students aren’t familiar with watersheds and river systems, refer them to the river system diagram. Explain to students that they are connected to rivers, and that their actions can affect the water quality in their watershed. You can find background information to lead this discussion at “Know Your Watershed.” (Conservation Technology Information Center)

Have you ever looked closely at a gutter or a storm drain? You probably saw litter: cigarette butts, candy bar wrappers, soda cans or bottles, grass clippings, chewing gum, paper.

Rainwater, melting snow, and water from garden hoses can easily wash litter and other matters into storm drains, and finally into ponds, lakes, rivers, or the sea. Such runoff can wash straight into streams, wetlands, and other surface water. This contaminates surface water and groundwater and poses risks to people, as well as to aquatic plants and animals. Pollution whose source is difficult to identify is called nonpoint source pollution.

Have students survey trash and other pollutants that could enter a storm drain. Write “Possible Pollutants” across the top of an 8 ½ x 11" page. Copy this survey sheet for each student. On their surveys, have students list items they see on their way to or from school that could potentially pollute a river. Or, lead the class in examining the school grounds or playground for litter. (For safety reasons, students should not pick up the litter.) They can make a hatch mark each time they see the same item.

After students have completed their surveys, discuss the results with the class. After class, try to find, and collect, some of the types of litter that students listed on their “Possible Pollutants” surveys. (Wear rubber gloves.)

Take a firsthand look at what might be going into rivers by surveying everything you see in gutters, near storm drains, on sidewalks, or around your school.

Dirty Water: At the Root of the Problem
Ask the class, What do plants need to grow? What are possible effects of polluted water on plant growth and health? Fill several small aquariums with clean water, and have students put aquarium plants in the containers. Have students drop the “sewer litter” you collected in one of the containers. They should add other pollutants (salt, oil, soap) to each of the other containers, and mark each container. Can students think of any other pollutants? Over the next few weeks, have students observe each container and record their observations.

Unfortunately, what you see in gutters isn’t all a river gets. Other nonpoint source pollutants such as salt, car oil, fertilizer, liquid soap, antifreeze, battery acid, and paint thinner may end up in rivers. River water is withdrawn for industrial or agricultural use, and then often polluted by industrial waste or fertilizer, or it may be heated—causing problems for plants and animals in and along the water and for people downriver.

How does all that stuff affect rivers? Over the next several weeks you’ll see for yourself as you observe plants in water that you will pollute.

What’s the State of Your River?
Students can find data on “Water Where You Live” from the Environmental Protection Agency. Prior to the activity, click through the site, which is detailed and technical, so you can offer students direction. Students can find maps that show how watersheds cross over political boundaries, which can prompt a class discussion about control and cooperation between states. Students can also find interactive maps, and examples of how to organize geographic information visually, through maps, charts, graphs, and tables. (U.S. Environmental Protection Agency)

As you’ve watched the plants in polluted water, have you wondered about the state of your state’s rivers? Go to http://www.epa.gov/OW/states.html and click on your state to see how the Environmental Protection Agency monitors water quality. Check the Index of Watershed Indicators: Does your county measure up? (U.S. Environmental Protection Agency)

Take Action—Geography Action!
If students don’t have access to computers, you can print out Pollution Prevention Tip Cards, which explain ways of reducing stormwater pollution. Encourage students to take the cards home and ask family members to help protect rivers. (Clinton River Watershed Council)

Have your class join other students in an annual, collaborative project testing freshwater rivers, streams, lakes, and ponds around the world. To learn more, go to http://k12science.org/curriculum/waterproj/. (Global Water Sampling Project)

If you participate in a river cleanup, do so safely. If you don’t live near a river, you can protect rivers (and oceans) by stenciling signs on storm drains. (U.S. Environmental Protection Agency) (National Geographic Society)

Keep your family on track by tracking their use of fresh water. (National Geographic Society)

Whatever you decide to do, tell us about it! Fill out the Geography Action! survey, and learn what other students are doing for rivers!

Activity adapted from “All About Water—K-3 Water Activities” Booklet, courtesy of the California Department of Water Resources.

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Photographs (left to right): Lower Monumental Dam, Snake River, Washington, by Richard S. Durrance; natural spring, Florida, by Wes C. Skiles

Illustration (right): Dragonfly, copyright Corbis

© 2001 National Geographic Society. All rights reserved.