Contaminated Drinking Water

About this Lesson from the Ecology Center

Recommended Age Groups: Early Elementary, Later Elementary

Guiding Question: Can our taste buds and eyes detect unsafe drinking water?







  1. Two cups of water
  2. Small pile of table salt
  3. One cup of vinegar
  4. Teaspoon
  5. Handout

Room Preparation:

Students need tabletop space, elbow room, access to water and clean-up materials.

Safety Precautions:

Water, salt, and vinegar may spill. Avoid getting vinegar or salt in eyes.

Procedures and Activities


  1. Is the water we drink safe? How can we tell if it is safe or not? What materials are in our water?

  2. Today, we will see if we can tell if our water is safe to drink by looking at it and tasting it.


  1. Give each pair or small group their materials and handout.

  2. Go over the roles needed:

  3. Explain the experiment process. First add one teaspoon of salt at a time to one cup of water. Stir each time, taste, and document what is seen and how it tastes on the hand-out. Stop when it tastes too bad to drink. Repeat the process with new glass of water and vinegar.

  4. Ask if students know when there is too much salt or vinegar in the cup for their bodies to safely handle? Share that too much salt is very risky for people with blood pressure, heart, or other health problems, yet sometimes we don't know that what we are drinking is harmful to us.

Closing - Original Question

Ask again: "Can our taste buds and eyes detect unsafe drinking water?"


During class discussion, note if students understand concepts of drinking water, ground water, and the principles of pollution or contamination, and conclude that we often cannot tell by taste or observation what is in our water or if it is safe to drink. Students may make oral or written presentations to share their experiment, observations, and findings.

Extension Ideas

  1. Draw a bar graph comparing the amounts of salt and vinegar different "tasters" found to be undrinkable. Talk about our individual taste bud differences and that taste is not a reliable indicator of harm.

  2. Have students research table salt and other chlorides (like road salt) to learn more about this seemingly harmless substance. Students may talk to nurses, doctors, people with heart and blood pressure problems, dieticians, road commissioners, environmentalists, and natural resource specialists. Students can share findings by oral presentation or written report. Students will see the profound impact something like salt can have on us and on our ground water.

  3. Have students think about what they can do to clean and preserve the earth. Encourage students to put their ideas to use. To get started, review 20 things we can do to help reduce pollution and preserve our Earth.

  4. Plan an environmental field trip:

  5. Explore the wealth of data collected by the federal government, such as the National Hydrography Dataset, or the U.S. Environmental Protection Agency's Surf Your Watershed, or other information available through the U.S. Geological Survey.

Careers Related to the Lesson Topic

Prerequisite Vocabulary

Contaminated Water
Water that has become mixed with a poison or another material that may—if there is enough of it—be dangerous to those who drink or use it

Drinking Water
Water (usually from under the ground or on the surface, as in lakes or rivers) that we use for cooking, drinking, washing, and so forth

Water that sinks into the earth and supplies wells and springs

Not poisonous


Harmful and poisonous materials or substances

      Lesson provided by Ecology Center, 734-995-5888, 117 N. Division St., Ann Arbor, MI 48104

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Last amended 20 Mar 2000