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.
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
Refer students back to the two jars and ask them which is the pollutant and which is the
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.
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.
Water Contamination: The dirtying of water resources by natural materials
Water Pollution: The dirtying of water resources, especially by human-generated wastes
SD Standards for 4th grade:
Nature of Science Idicator 2
Interpreting (identifying cause and
effect), Critical Thinking, Cooperative
Prior Preparation: Gather all
materials together to complete the
water contamination, water pollution