Aquifer in a Cup
To illustrate how water is stored
in an aquifer, how this water can
become contaminated, and how
this contamination ends up in a
drinking water source.
1 clear plastic cup – for mode
beaker of water
1 piece of modeling clay
red food coloring
• Pour sand into the bottom of the cup until it is
1 cm deep and covers the bottom.
(see D in diagram)
• Pipette water onto the
sand wetting it just
enough that there is no
standing water on the
• Flatten the modeling
clay like a pancake
and cover half of the
sand with it.
• Press the clay against
the side of the cup to seal off that side. This
represents the “confining layer” that keeps water
from passing through.
• Pipette 5 – 8 drops on the highest point of the
clay. (Question 1) Make observations on your lab
sheet. These need to be 3-4 sentences!
• Use the rocks to form the next layer of earth.
• Place the rocks over the sand and clay, covering
the entire container.
• To one side of your cup, slope the rocks, forming
a high hill and a valley (see diagram). These layers
some of the many layers
contained in the earth's
• Sprinkle ¼ teaspoon of the cocoa on the top of
the hill. The cocoa represents lawn chemicals
and fertilizers used by homeowners and
• Now pour water into your aquifer until the
water in the valley is slightly below the top of
the hill, but at least covers the cocoa layer.
Wait a minute, then record your observations
answering Question 2. This need to be 3-4
• Use the food coloring and pipette a few drops
on top of the rock hill as close to the inside
wall of the cup as possible. The red food
coloring represents chemicals, motor oil, and
other trash that is put in landfills.
• Wait about 1 minute, then
record your observations
answering Question 3. This
need to be 3-4 sentences!
8. What changes can you personally make to
improve the water quality in Friendswood?