MnSTEP Teaching Activity Collection > MnSTEP Activities > How Does Water Get Polluted?

How Does Water Get Polluted?

Deb Verdoorn Anderson, Madison Elementary, Blaine, MN Anoka-Hennepin ISD #11, based in part on information gathered from Adapted from SEE-North Ground Water, Education in Michigan's Schools- Science and Environment 1991
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Hands-on modeling of how pollution spreads in our ground and surface water.

Learning Goals

Given a water table model, students will observe and record as pollution infiltrates the ground and surface water. Students will discuss and write in their journals about their observations concerning pollution.

Context for Use

The lesson was designed for fourth grade ESL/ELL students, ranging from advanced beginner to intermediate, following the Water Unit. The group is divided into smaller groups of 2-3 children. It is a hands-on modeling and observation of the effects of pollution. The lesson will take approximately 35-40 minutes. Prior knowledge should consist of ground and surface water, water table, and pollution.

Subject: Environmental Science:Water Quality and Quantity:Non-Point Source Pollution, Geoscience
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

Overhead transparency of ground water diagram. (Microsoft Word 936kB May5 11) Student handout, water maze (Microsoft Word 46kB Jul26 07)
  • Clear plastic cups, 12 ounce size, taller and thinner
  • Gravel
  • Sand
  • Eyedroppers
  • 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.

Guided practice:
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

This activity should not be done until after the students have completed the water unit. It is an easy lesson that helps the students understand how pollution (fertilizers, oil, etc.) gets into our ground water. There are few supplies needed and set up is fast and easy.


Conclusion/Formative Assessment: Have the children talk about what they saw. How can they relate this to pollution? What kinds of things do they see people doing to our land that can affect our water? Discuss the disposal of toxic chemicals and paints, etc. Have the children write in their journals about what they have learned about pollution. Those who cannot write may draw pictures of what they saw and diagram out what they believe to be the cause of pollution. They may also draw pictures of things they think may cause pollution.


Primary Content Standard: Inquiry 1A-E2, new benchmark, Science is a process of trying to figure out how the world works by making careful observations and trying to make sense of those observations.
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.

References and Resources