Midnight Dumpers

Summary: An illegal chemical dump has taken place and is polluting ground water in local wells. Using a model of "well" water, students will find the location of the illegal dump.

Learning objectives:

1. Students will master the following vocabulary words: ground water, aquifer, random sample, reservoir.
2. Students will explain how pollution affects ground water and learn how to discover the location of a pollution source.
3. Students will relate how monetary benefits, risk and environmental concerns are factors in business decisions.

Materials:

• 23 small opaque bottles (film cans, medicine vials)
• dark and light colored beans of the same size (Navy and Great Northern)
• dark food coloring
• map for each group
• student sheet for each student.

Background Information: Illegal dumping of chemical wastes is a national problem. Laws exist to prohibit the dumping of dangerous chemicals, but they can be broken fairly easily (usually at night). Disposal of chemicals is expensive and an unscrupulous corporation can save money by dumping illegally. Dumped chemicals seep through the soil and contaminate ground water. Legal chemicals (fertilizers, pesticides) do the same thing and students should be aware that they should never dump anything on the soil that they wouldn't want to drink.

Wells that pump from an aquifer (underground body of water) tend to draw water and any chemicals toward them. Wells are periodically tested to ensure a safe water source. Any sampling technique has an element of randomness. In this activity, randomness is modeled by requiring the students to return the beans(water) to the vial after each is pulled out. It is possible to get the same bean twice. Students will not want to do this so you need to be firm on this point. They can retest a well if they think the sample was inaccurate.

The student groups are models of environmental firms that work for government and industry groups who find and clean-up spills. They have to make a profit to stay in business. The fewer samples they have to take to correctly find the source of a spill, the more money they will make. An incorrect identification can ruin their reputation.

In this activity you need to prepare the vials in the following manner.

1. Label the bottoms of the vials with a permanent marker: 8 vials should be "A's", 4 should be "B's", 4 should be "C's", 3 should be "D's", 3 should be "E's", and 1 should be "F".
2. Fill the vials with beans in the following manner:
   • vial A - 18 dark beans, 2 light beans
   • vial B - 16 dark, 4 light
   • vial C - 12 dark, 8 light
   • vial D - 8 dark, 12 light
   • vial E - 6 dark, 14 light
   • vial F - 2 dark, 18 light
3. Before the activity, a key similar to the example on the next page should be made. You can pick any location for the spill and may want to vary it during the day. As students come to get their "samples" do not let them see the vials or the key.

See the student page for step by step instructions.

Sequence and Duration of Lesson Parts:

1. Introduction of ground water, aquifer, pollution and well relationships by teacher - 10 minutes.
2. Explanation of activity - 5 minutes.
3. Work time for students - 20-25 minutes.
4. Summary - 10 minutes

Evaluation: Students will know immediately if they identified the correct location. An analysis of the profit they made will determine which group was most successful from a business standpoint.

Appendix A - Midnight Dumpers Student Handout

Appendix B - Map #1

Appendix C - Map #2