An aquifer is an underground layer of rock, gravel, sand or silt through which water can easily move. This water can be extracted for human consumption through the use of a water well. Aquifers provide natural filtration that helps to purify the groundwater flowing through them. However, not all contanimants are rendered harmless by this purification process, and some pollution can still be found in the groundwater, making it unsafe to drink.
You can make your own model of an aquifer from things found in your grocery store. To start you need the following:
- Blue/red food coloring
- Vanilla ice cream
- Clear soda pop (7-Up, Sprite, etc)
- Small gummy bears, chocolate chips, crushed ice or other material to represent sand and gravel
- Drinking straws
- Clear plastic cups
- Ice cream scoop
- Fill a clear plastic cup 1/3 full with gummy bears, chocolate chips, or crushed ice. This represnts sand/gravel in your aquifer.
- Add enough soda to just cover the candy/ice.
- Add a layer of ice cream to serve as a “confining layer” over the water-filled aquifer.
- Then add more “sand/gravel” on top of the “confining layer.”
- Add a layer of sprinkled over the top to create the porous top layer (top soil).
- Now add the food coloring to the soda. The food coloring represents contamination. Watch what happens when it is poured on the top of the “aquifer.”
- Using a drinking straw, drill a well into the center of your aquifer.
- Slowly begin to pump the well by sucking on the straw. Watch the decline in the water table.
- Notice how the contaminants can get sucked into the well area and end up in the groundwater by leaking through the confining layer.
- Now recharge your aquifer by adding more soda which represents a rain shower.
- Eat and enjoy your aquifer!
Lesson adapeted from the Groundwater Foundation.