• Gather all necessary materials for students.
• Pre-cut the wire mesh/screening into 4" x 4" squares.

1. Review groundwater flow with students.
2. Pass out materials to each group.
3. Pictures of drinking water wells can be found at: http://www.epa.gov/safewater/uic.html
4. Explain how to make a well from the following procedure. It may be useful to make an example in front of the class and then let the students repeat the procedure in small groups.

To make the well:

1. Roll the piece of screening around a pencil to make a cylinder (see Figure 2).

Figure 2. The first stages of making the well. Copyright © Image created by Malinda Schafer Zarske, University of Colorado at Boulder, 2005.

2. Enlarge the cylinder to approximately one centimeter in diameter and secure at that diameter with the piece of wire or garbage/bread bag tie.

Figure 3. Actual creation of the well. Copyright © Image created by Malinda Schafer Zarske, University of Colorado, Boulder, 2005.

3. Place the screen cylinder in the middle of the jar and hold steady while pouring sand around the outside of the screen (see Figure 4).

Figure 4. Sand filled around the wire mesh cylinder. Copyright © Image created by Malinda Schafer Zarske, University of Colorado, Boulder, 2005.

To model well water and pollutants:

1. Ask the students to determine a question about contaminants that they would like to answer during this investigation.
2. Remind students that the sand in the jar/can is considered the land surrounding their well, and the wire mesh cylinder is their pump.
3. Students should pour ½ cup of water onto the sand in the jar.
4. Ask students to remove water from the well using the medicine dropper. This is their water "pump." Student should make observations of the "look" of this water (for example, clear or sandy.)
5. Have students determine a "contamination site" in their jar — where the landfill or chemical contaminants will be added to the sand. Ask them to add five to six drops of food coloring as the "pollutant" to that site.
6. Have the students measure depth of the water well before the "rainfall." They should write this number on a piece of paper.
7. Students should carefully add ½ cup "rain" water to the sand (their land) in the jar.
8. Have them remove a sample of well-water using the medicine dropper (pump). They should make observations of the condition of this water (such as colored or clear.)
9. Have the students measure depth of the well water after the "rainfall." They should write this number on a piece of paper. How did the water level change? How would the water level change the amount of pumping that would be needed to get the water from the well? (Answer: higher water levels are easier to pump)

Discussion: What does an engineer need to consider when building a groundwater well? (Answers may include: an engineer would need to consider the water table height for how far to dig the well, and nearby sources of possible pollutants.)

Journals: Have students record their procedures, predictions, observations and conclusions in their journals. Students should be very thorough and complete.

Question/Answer: Ask the following questions:

• What happened to the groundwater when you removed water from the well? (Answer: The level of the water in the jar went down.)
• What happened to the well water when the "pollution" was added to the "soil?" (Answer: The water in the well turned the same color as the pollution added.)
• How does the water table change? (Answer: The water table increases height when there is "rain" and decreases height when water is removed from the well.)

Inform the community!: Have student groups create an informational flyer to illustrate how pollutants move from ground surface to aquifer to drinking well. Pass the flyer to another group (the community) and have the second group write on the back of the flyer one compliment, one criticism, and one question. Pass the flyers back and talk about the questions as a group. Display the flyers around the room or school to inform other members of the community.