Materials:
Aluminum baking pans
Unsweetened lemonade-flavored powdered drink mix
Books to raise the end of the pan
Sand-Enough to fill baking pan
Straws
13 pH papers
Misting bottle
Beaker of water
Procedure:
1. After students have been divided into small groups inform them that they are a well drilling company that tests quality of ground water.
2. Each group should have an aluminum pan filled with about 2 ½ inches of sand.
3. Mark one end of the pan with an X.
4. Have the students hide the contaminant-the lemonade flavored mix somewhere in the sand.
5. Draw a map and mark where the powder is located and then switch their pan with another group.
6. The task is to now find the site of contamination using only the pH testing strips you have been given.
7. Raise the end of the pan that is marked with an X and sketch the pan for your data sheet.
8. Fill a misting bottle with water. Test the water’s pH and record the pH on the data sheet.
9. Create a gentle rain by misting the pan with water for about 5-10 minutes. No surface run-off should occur.
10. Fill a beaker with water and rinse the straw with water.
11. Begin testing the area for contamination by placing the straw over the suspected source of contamination. Remember to record your drilling site on your map.
12. Press the straw into the sand while plugging the top of the straw.
13. Carefully life the straw from the sand and place a small amount of the sample on the pH paper.
14. Observe and record the results.
15. Rinse the straw and repeat 11-14 until the contamination site has been found. Mark the contamination site with an X.
16. Compare your result with the group you switched trays with to see if you did find the contamination site.
Map of hidden contaminant tray Map of unknown contaminant trayU
*Remember the raised end of the tray is marked with an X
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Clean Water Sample
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pH
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Possible Contamination Site
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pH
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Contamination Site?
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Discussion Questions
1. How did you determine the site of contamination?
2. How does this activity help you understand how materials move through watersheds?
3. How does this apply to the real world-what challenges would you face in trying to locate the source of contamination?
4. What difficulties would you face in trying to clean the contamination?
- This activity will help all of the experts delve further into their topic. The watershed expert can think about how materials move in watershed. The legislation expert could think about what materials leach into the ground water and what legal action is taken in such cases. The water treatment expert could think about how to clean the area and how to purify the water.
Adapted from Project WET curriculum
