Edible Earth Parfaits

Here's a fun, easy and tasty way to understand the geology of an aquifer....the source of the groundwater that many of us get our drinking water from. As you make your earth parfait, you will see what a cross-section of a typical aquifer looks like and how pollution can get into groundwater and how pumping a water well can cause a decline in the water table.

Materials Needed:

• Blue or red food coloring
• Vanilla ice cream
• Clear soda pop
• Crushed ice
• A variety of colored cake decoration sprinkles and sugars
• Straws
• Clear plastic cups

Activity Steps:

1. Fill a clear plastic cup one-third full with crushed ice (which represents the gravels and soils in our aquifer).
2. Add enough soda to just cover the ice.
3. A layer of ice cream is added to served as a confining layer over the water-filled aquifer.
4. Crushed ice is added on top of the confining layer."
5. Colored sugars and sprinkles represent soils and should be sprinkled over the top as the porous top layer.
6. Blue or red food coloring is added to the soda. This colored soda represents contamination and is poured on the top of the "aquifer." as you watch the colored soda infiltrate the "confining layer" (the ice cream), you can see how contamination moves and the overall vulnerability of aquifers to spills on the earth's surface.
7. Straws can be used to drill a well into the aquifer. Pumping (sucking on the straw) the well demonstrates a decline in the water table.
8. You should be able to see how the contaminants get sucked into the well area and end up in the groundwater by leaking through the confining layer.
9. Your aquifers can be recharged with additional soda "rain" and re-polluted with more colored soda.

For a recipe to "edible aquifers" and other fun, educational activities to help protect our groundwater, contact The Groundwater Foundation at P.O. Box 22558, Lincoln, NE 68542-2558, (402)434-2740 or on the Internet at www.groundwater.org.