How Does Water Get Polluted?
Hands-on modeling of how pollution spreads in our ground and surface water.
Context for Use
Resource Type: Activities:Classroom Activity:Short Activity:Demonstration, Activities:Lab Activity, Classroom Activity
Grade Level: Intermediate (3-5)
Theme: Teach the Earth:Teaching Environments:K12, Teach the Earth:Course Topics:Environmental Science, Teach the Earth:Teaching Topics:Water
Description and Teaching Materials
- Clear plastic cups, 12 ounce size, taller and thinner
- Green food coloring
- Glasses of water
- Overhead transparency of ground water diagram (See example following this lesson.)
- Handouts (1 per child) water maze (See example following this lesson.)
Introduction: (To get the students thinking)
Hand out the water maze to each student. Explain that they are trying to find a way from the start to the water table. Allow them a few minutes to work on it. Ask the class if what they were doing reminded them of anything else they have done or observed. (Previous lesson was on building and filling a water table)
Explain that they have just taken a path that a raindrop may have taken in order to reach the water table. What will happen to the water table as the rain continues to fall? What will the rain fill up? Show the overhead, Ground Water Diagram. Show on the picture where the ground water is, where the water table is, and where the surface water is. Any questions or clarification needed? Tell the class each group will be getting another cup today, this time with both sand and gravel in it. The sand will be at the bottom and the gravel on top. They are going to make a model that shows pollution.
Divide the class into small groups of 2-3 students. Give each group a cup with sand on the bottom, and gravel on the top. Have someone in the group make a hill out of the gravel, make it fairly steep. There will be some sliding of rocks down the hill, but that is okay. Hand out the glasses of water and the eyedroppers. Tell the children they will be making rain with these. Go around the classroom and drop one drop of green food coloring on top of the hill near the side of the glass. Once everyone 'has been polluted', tell the groups they are going to rain on the hill. They must rain in a gentle way, so that no rocks are disturbed. They are to use the eyedroppers to draw up the water and expel it gently on the hill. Watch to see what happens to the pollution. (The class is amazed when they see the green go down the side of the glass and eventually into the water supply.)
Teaching Notes and Tips
Primary Content Standard: 4B-4, Freshwater can be depleted and polluted.
ESL Standards: Goal 2, Standard 2, To use English to achieve academically in all content areas.