Allow the water table to remain undisturbed overnight and encourage the students to observe how it has changed. Soil pollutes water by making it unclean. The water clears as it stands. Water is safe to drink when it is clean and not polluted. Please stress to the students that while water may look clean, it may contain harmful, invisible germs which could cause illness.
Polluted water is never safe to drink.
Go on a field trip to a pond and observe the water plants and wildlife that lives in the pond. Discuss how the water is polluted and what effect it has on the animals and plants. Encourage the students to bring pictures of rivers and lakes. Discuss how the water comes to the local storage area. Add other substances to the water table such as cooking oil and food coloring.