What's The Difference?

Objective: Students will be able to distinguish between water pollution and water
contamination. They will also be able to identify water pollutants and water contaminants.

Materials: pitcher of tap water, 2 clear quart jars, small amount of bleach, fertilizer, detergent,
motor oil, vinegar, soil, small leaf, twig, and dead insect

Background: Water contamination is pollution that occurs when materials of natural origin (such
as soil, silt, or algae) gives water an earthy, fishy, woody, or other unpleasant taste or odor or
discolors it.

Water pollution is pollution that occurs when unwanted wastes (such as sewage, industrial
wastes, and agricultural wastes) are released into water sources. This is a result of human
activities.

Procedure:
Gather contaminants: small leaf, twig, dead insect, and soil.

Gather pollutants: fertilizer (represents agricultural waste), bleach and vinegar (represents
industrial waste), and detergent and motor oil (represents domestic waste). Make sure all
pollutants are properly disposed of after use (read labels carefully).

Pour water into the two jars until they are about half full. Ask if there is any difference between
the two jars of water.

Add a pollutant to one of the jars and a contaminant to the other. Again, ask if there is a
difference between the two.

On the chalkboard, write the words "Water Pollution" and "Water Contamination" and draw a
vertical line between the two to make a chart. Under Water Pollution write "Human cause" and
under Water Contamination write "Natural cause". Explain the difference to the students, giving
examples like: After heavy rain, streams and rivers sometimes turn "muddy" because they are
carrying a lot of silt that washed into the river from the land. Sometimes in the summer, a lot of
algae grows in the water and makes it taste bad. These are examples of water contamination. If
people cause things like chemicals or human or animal wastes to be put in streams or rivers, this
is called water pollution.

Refer students back to the two jars and ask them which is the pollutant and which is the
contaminant.

Have students fold a piece of paper in half lengthwise. Ask them to draw a line down the fold,
then label the left side "Water Pollution" and the right side "Water Contamination".

In indiscriminate order, hold up the pollutants and the contaminants and explain what they are
and what they represent. As you hold them up, have students write down whether it is a
pollutant or a contaminant in the corresponding column.

After you've displayed all the materials, go back over them with the students and ask them to
tell you which column they belong in and why. Be sure to stress the difference: Pollution is the
result of humans; contamination is the result of natural causes. Have students check and correct
the charts.

Extensions:
Have students write a story about water pollution from a bear's point of view.

Have students draw a simple picture of a body of water (creek, river, lake, etc.) with a pollutant
in it on one side and a body of water with a contaminant in it on the other side. Below the
pictures, students can write sentences telling what the material is, whether it is a pollutant or
contaminant, and why they classified it as such. You can display their artwork on a bulletin
board.

Have a representative from the public health department come to talk to your class about water
pollution and ways to prevent it.

Vocabulary Glossary:
Water Contamination: The dirtying of water resources by natural materials
Water Pollution: The dirtying of water resources, especially by human-generated wastes