Building an Aquifer in a Cup

Materials Needed:

• Two (2) clear cups of water.
• One (1) cup of sand
• One (1) cup of gravel
• One (1) cup or watering can filled with water
• One (1) package of Kool-Aid drink mix or food coloring

Remembering that groundwater is the water stored between the spaces in rock, sand and gravel, you are now going to get the chance to see it for yourself with this little experiment.

1. Layer different amounts of sand and gravel to about 3/4 from the top in both of the cups. In real life, aquifers consist of layers of sand, gravel and rock. Nearly 90 percent of all aquifers are comprised of sands and gravels.
2. In the first cup, pour or sprinkle water slowly into it. Watch how the water fills the spaces between the particles of sand and gravel. This is what happens when rain or melting snow soaks down into the ground. Go ahead and fill the cup with water above the sand. Water that is located above ground, like rivers and lakes, is called surface water. Water below the ground's surface is called groundwater.
3. In the second cup, pour water almost to the top of the sand, but not all the way up. Can you see where the top of the water is? This is called a "water table." Water below this line is called the "saturated zone."
4. Now, imagine that the Kool-Aid or food coloring is a groundwater contaminant. Many different things, if not used carefully, can contaminate groundwater. Sprinkle the Kool-Aid, or put several drops of the food coloring into the "aquifer" in the second cup. Let your aquifer sit for a few minutes and watch what happens.
5. Ask yourself these questions....
   • How would I get the water out of the ground?
   • How long did it take for the contaminants to get through the aquifer?
   • Do I want to drink this (remember, it's contaminated).?
   • How can I get the contamination out?

(Taken in part from "The Groundwater Gazette," Volume 1, #1, Fall, 1998).