|Objective||Students will demonstrate through building a model how aquifers are formed and ground water becomes polluted.|
|Duration||One 1 1/2 hour period|
|Skills||Observation, Analysis, Discussion, Experimenting, Media Construction, Comparing Similarities and Differences|
|Grade Level||3-6 (if teacher performs demonstration); 7-12 (if students build model)|
|Vocabulary||ground water, pollution, aquifer|
|Materials||For each model
With younger students, the teacher should build the model as a demonstration. Older students can be divided into small groups to build the model, or can each build the model individually if there are enough materials. Have them use the Groundwater Model handout for reference.
1. Define ground water and aquifers. Discuss with students the importance of ground water in the United States and the Ohio River Valley.
2. Secure nylon fabric over one end of the plastic tubing with masking tape or a rubber band.
3. Tape the tubing to the inside of the tumbler so that the nylon covered end of the tubing almost touches the bottom of the tumbler.
4. Fill about one-third of the tumbler with pebbles.
5. Cut the filter paper into a circle with a diameter slightly larger than the diameter of the inside of the tumbler. Place the filter paper on top of the pebbles and tape it securely to the sides of the tumbler.
6. Fill the rest of the tumbler with sand.
Note: A shallow layer of potting soil can be added on top of the sand to represent the Earth's crust.
7. With the sprayer, apply water to the sand until it is saturated. The water will filter down into the pebbles.
8. Put the end of the syringe into the tubing and make sure the connection is tight.
9. Pull back the plunger of the syringe to create a vacuum. Water will be drawn from the pebbles/sand into the tubing and ultimately into the syringe. Discuss with students that this represents how ground water is pumped from aquifers.
10. Add a few drops of red food coloring to the sand. Explain to the students that the red food coloring represents a pollutant. Discuss what kinds of substances can pollute ground water.
11. Apply more water to the sand.
12. Continue "pumping" water from the tumbler with the syringe. When the syringe fills with water, remove it from the tubing and pour the water into the clear glass container. Refasten the syringe to the tubing and continue "pumping" water. Ultimately, the water in the clear glass container will have a reddish hue. Discuss with students how the "pollutant" applied at surface level has "contaminated" the "ground water" in the experiment.
|Discuss with students how groundwater contamination occurs in real-life situations and how it can be prevented. In additional, a film or filmstrip can be shown on ground water.|