Bottled vs Tap Water

Preparation: The water samples should all be at the same temperature. It is also important to take the water samples out of their original containers if they are something special, such as Fuji water or Smart water. 

Engagement: Take a poll of the students in the class. Ask the students if they drink mostly tap water straight from the tap or water fountain, if they filter their tap water with something like Brita or the filters that go over the faucet, or if they drink bottled water. Tally the numbers on the board. Then ask the students if there is a particular brand of bottled water they prefer. Record these results on board also. Students often prefer ‘spring water’ to tap water. Make sure that students understand what a spring is, and why it is considered a ‘pure’ source of water. If students don’t understand the importance of soil as a filter, you may want to complete the “Soil Filter” lesson with them.

Exploration: Give each student a cup, and go around the room with different water samples for the students to taste (labeled with numbers). Have students compare their results in small groups and then as a class which water sample they liked the most and least (on a scale of 1-10), any odors. Discuss the results with the class.

Next, provide copies of local municipal water treatment reports (several examples from Kingston, New York City, and Poughkeepsie are provided with this lesson, but it would be more effective to have your own town or city’s results) as well as examples of bottled water quality. Students will use the reports to answer the questions on the worksheet.

Explanation: Using the powerpoint presentation as a guide, discuss the sources of the various waters including where tap water comes from and the sources of the bottled waters. Chlorine is usually added to tap water and different minerals or electrolytes may be added to bottled waters. Discuss why taste alone is not a good judge of whether or not water is safe. Since the FDA regulates bottled water (the EPA regulates tap water), the regulations are not as stringent. In addition to the safety concerns, there are huge environmental and social impacts associated with using bottled water. Connect to climate change issues by mentioning the transportation impacts and plastic bottle manufacturing process.
 

Extension: Have students create bar graphs for water type vs. number of students and bottled water preference vs. number of students. Read articles, “Which Water is Tastiest?” and “The Purity Factor” from the New York Times, 2004.

Evaluation: Collect student worksheets.