Before Class:

1) Use a tomato soup can (remove label) or any can that can be easily emptied of it's contents by pouring through a hole. See Figure 2

2) With an old ice pick or similar sharp object, bore a hole at one end on the curved side as seen in Figure 1. Empty the contents of the can. Rinse several times. With a sharp knife point, punch tiny holes (5 or 6) at both ends of the can. Make these tiny holes near the seal at both ends of the can. (All of No. 1 and 2 can be done prior to class time.)

During Class:

For the following, assemble just before class time or during class if time permits:

3) Fill the can with water in which 4 or 5 drops of red cake coloring have been added. Place a plastic straw in the large hole secured with a bit of play dough or similar material (not air tight, because later you will show that gas can leak where this pipe is not sealed to the tank opening and through the tiny holes that have been punched in the can.

4) Place the entire set-up in a plastic bag (to catch leaking) or immediately submerge in a clear plastic box and pour sand or dirt around and on top so that the straw stands about 2 inches above the surface of the dirt. Place the "tank" near the side of the plastic box so that leaking of the colored water (gasoline) from the "leaking underground storage tank" can be seen through the clear plastic wall of the box as seen in Figure 2. Gasoline contains many hydrocarbons and organic chemicals that seep out into the soil and into ground water that leads to your drinking water wells and creeks, streams and rivers.