EXPERIMENTS

Edible Earth Parfaits

Background:

This activity is a fun and easy way to understand the geology of an aquifer. You will build your own edible aquifer, learn about confining layers, contamination, recharge and water tables.

Materials Needed:
  • Blue or red food colouring
  • Vanilla ice cream
  • Clear soda pop
  • Crushed ice
  • Variety of coloured cake decoration sprinkles and sugars
  • Drinking straws
  • Clear plastic cups
Objective:

This activity will teach you about the geologic formations in an aquifer, how pollution can get into groundwater and how pumping can cause a decline in the water table.

Activity Steps:
  1. Begin to construct your edible aquifer by filling a clear plastic cup 1/3 full with crushed ice (represents gravel and soils).
  2. Add enough soda to just cover the ice.
  3. Add a layer of ice cream to serve as a "confining layer" over the water-filled aquifer.
  4. Then add more crushed ice on top of the "confining layer".
  5. Coloured sugars and sprinkles represent soils and should be sprinkled over the top to create the porous top layer.
  6. Now add the food colouring to the soda. The food colouring represents contamination. Watch what happens when it is poured on top of the "aquifer". Keep in mind that the same thing happens when contaminates are spilled on the earth's surface.
  7. Using your straw, drill a well by sucking on the straw. Watch the decline in the water table.
  8. Slowly begin to pump the well by sucking on the straw. Watch the decline in the water table.
  9. Notice how the contaminants can get sucked into the well area and end up in the groundwater by leaking through the confining layer.
  10. Now recharge your aquifer by adding more soda which represents a rain shower.
  11. Review what you have learned as you enjoy eating your edible aquifer.

Edible Earth Parfaits was adapted from Making A Bigger Splash, co-published by The Groundwater Foundation and the US EPA Region VII.

Where Does Your Water Come From? Taste Test

Background:

Every day, the average Canadian uses about 50 liters of water for drinking, bathing, cooking and maintenance. Most people, however, are unaware of the source of their water. In Grey & Bruce Counties, about 57% of the population is supplied by community water supply systems. The other 43% is supplied by non-community means, such as campgrounds, resorts, and private wells. 71% of public water systems use surface water as their source, the other 29% use groundwater from wells. The aesthetic properties of the drinking water from these public systems is often affected by the source of the water. Groundwater often has a slightly metallic taste, and may contain high amounts of minerals. Surface waters, on the other hand, usually have a musty taste and look cloudy. Treatment techniques aim to produce a water that is: safe for human consumption; appealing and good tasting to the consumer; and conforms with applicable Canadian & Provincial regulations at the lowest possible cost.

Objective:

This taste test will illustrate the differences between groundwater and surface water, highlight some of the common contaminants in natural water, and encourage student thought on the sources of drinking water.

Materials Needed:
  • 1 liter of distilled water
  • 1 liter of tap water (identify the source) Try comparing two different municipal supplies!
  • 1 liter of mineral water
  • 1 liter of filtered tap water
  • Cups
Procedure:
  1. Label each cup 1 through 4 and fill them with the different types of water.
  2. Identify the different tastes, smells, and appearances in the water. Write down your observations on each water sample, and guess which cup has which type of water.
  3. Mark down your guesses and reveal which samples contained which type of water.
Follow Up Questions:
  1. What are some possible sources of water in your community?
  2. Which type of water tasted best? Why?
  3. Which type of water would you consider safer to drink, groundwater from a spring, or surface water from a stream?