Activity 1: A Model Aquifer
This activity will help students understand how Cape Cod's
ground-water system is unique and how contamination spreads easily
underground. To do so, students will build a model of an aquifer. They
will "recharge" the aquifer by pouring water into designated areas in
the model and collecting water from holes they have made in the box
holding the model. By doing this activity, students will determine how
water moves through the aquifer and which materials make the "best"
Each group of students will need:
- a clear rectangular 3-gallon-sized, plastic box or tub. Use the longest box you can find,
- potter's clay or natural clay soil,
- measuring scoop made of a plastic gallon milk jug with the top cut off,
- graduated cylinder,
- two pie plates or petri dishes for catching water that flows out of the aquifer,
- a ten-penny nail for making holes in boxes,
- water, and
- a copy of the illustration of the model aquifer.
|Model Aquifer (Activity 1)
students to the diagram of the aquifer. Tell students that they will be
working in groups to build model aquifers. Explain that different
groups will be using different mixes of materials in their aquifers.
Some will be using all sand; some will be using all gravel; some will
be using a mix of sand and gravel.
- Instruct students to punch holes in the plastic tub. Holes should be no smaller than 1 mm and no larger than 2 mm.
- Have students measure out the different aquifer
materials using the measuring scoop. Make sure each group uses the same
volume of material - sand, gravel, or half and half - for the aquifer.
Have the students who are using the half-sand half-gravel mixture
prepare the mixture before measuring it or packing the mixture into the
- Students should then pack the tubs with the "aquifer"
materials. The bottom layer of clay should be very thin - 2 mm - and
well packed. Students should then add the aquifer material - 2-3
scoops, depending on the size of the tub. The upper layer of clay - 1-2
cm thick - should also be well packed.
- The next step is to elevate the tub or place it on
the corner of a table so the holes where water will emerge are
accessible. The tub could be elevated with coffee cans or blocks, or
placed diagonally on a table corner. Students should position the two
pie plates or petri dishes to catch the water that comes out of each
- To observe how the aquifer model works, students
should pour water in the hole in the clay at the top, 10 mL at a time,
until drops appear at the holes. After drops appear, students should
pour in one final graduated cylinder full of water. Students should
record the amount of water that is poured into the model. In the pie
plates or petri dishes, they will collect the water that comes out of
each hole, then measure the amount of water in an empty graduated
- When students have finished pouring water into their
aquifer models, gather the class together. Have the students in
different groups compare the water-holding capabilities of different
- Refer students to the section of the Student Packet
that explains porosity and permeability. Review these concepts. Then
hold a general discussion of what students expected to discover and
what actually happened. Students are likely to be surprised to find
that even a thin layer of impermeable material will not allow water
- Describe how a town built on top of this model could access and use the water in the aquifer for its water supply.
- Invite a local well driller to class to discuss information related to local aquifers, drilling depth, and costs.
Back to top