Understanding the Energy Demand of Bottled Water

Apr. 15, 2011 | 0 Comments | Language Arts | Math | Science | Social Studies | 5-8 | Energy

Lesson Steps

Warm-up: A Bottle of Oil

1. Present students with a plastic water bottle filled one-fourth of the way with “oil.” (Cooking oil or a substance that looks like oil such as coffee would work well.)

a. Ask students if they are familiar with the concept of “embedded energy” or “energy footprint.” Embedded energy is also known as “Cumulative Energy Demand,” and represents the sum of all the energy inputs into a product system, from all stages of the life cycle (for example, extraction of materials, processing, transportation, manufacture, etc).[1]

b. Explain that you brought in this bottle to illustrate that drinking a bottle of water is like using this amount of fossil fuels. One-fourth of a bottle of oil or other energy source is embedded in the production costs of a bottle of water.

c. The point is that many products require the use of fossil fuels such as oil in order to be produced and transported to consumers, but we often are not aware of how much energy is used or in what ways. “The Pacific Institute estimates that the total amount of energy required for every plastic bottle is equivalent, on average, to filling each plastic bottle ¼ full with oil.”[2]

2. Let your students know that in this lesson they will be learning about the specific ways energy is used to bottle water and transport it to them. As consumers they have the power of choice, and their choices have impacts. Explain that you want them to consider the pros and cons of drinking bottled water versus tap water and they will be having a debate on this. Let them know that there is no right or wrong opinion, but that you want them to think carefully about the pros and cons of each type of water and the impact of the choices they make.

 

Activity One: Illustrating the Energy Used in Making Bottled Water

1. Pass out copies of Reproducible #1 – Steps in Getting Bottled Water to You. This handout describes the steps where energy is used.

2. Put students in groups of 3-4 and explain that you would like them to illustrate the many steps in which energy is embedded in the process of obtaining bottled water and transporting it to consumers such as themselves. Explain that you would like them to illustrate these steps on a large piece of butcher paper. Your students can organize their poster the way they prefer; a web-like illustration with arrows connecting one step to the next might work best. Be sure they include all steps from source to hand. Encourage them to be creative. Remind them that they do not need to be masterful drawers – in fact a cartoon effect and a little humor are great! The point is for them to better understand all of the energy that is required to produce a plastic bottle of water.

3. You may want to share all or some of the facts on Reproducible #2 – Record of Drink Bottles Used in a Week for students to incorporate into their illustrations.

4. Provide enough class time for the completion of the illustrations. Circulate among groups as they work, asking students to explain their work to you. Urge them to add a little text to describe each step for other people who look at their drawings.

5. Have students share their group’s work with the rest of the class. Discuss these with the class. Did they learn anything new? Did any groups think of something that others did not have?

6. Exhibit the large illustrations on classrooms walls or in the hallway so students can enjoy each other’s work and share the information with other classes and teachers.

 

Activity Two: Discussion Your Choices

1. Ask students how much they pay when they buy a liter of bottled water. Average will likely be between $.60 - $2.00 per liter depending on location and brand.

2. Then, tell them that the Army Corps of Engineer’s Washington Aqueduct pays $155 in energy for the collection, treatment, and transportation of one million gallons of drinking water to the Washington, DC metropolitan area.[3] This costs far less than one cent per liter of drinking water.

3. Discuss the economic benefits of tap water vs. bottled water. To explore this further, consider implementing the Extension at the end of this lesson – Calculate the Cost of Drinking Water in Your Municipality.

4. Remind students that, in addition to economic costs, all products have environmental costs as well. One of these is included in a product’s embedded energy – the energy used in all steps of extracting, processing, producing, and transporting the product. This energy is often “invisible” and we tend not to think about it, but the embedded energy has real impacts. Whether to buy or drink bottled water seems like a small decision, but there are significant ecological consequences that students are now more aware of.

 

Activity Three: Reducing the Energy Footprint of Your Drinking Choices

1. Revisit the idea of an energy footprint. Remind students that a product’s energy footprint is the amount of that product’s embedded energy. Students can have an energy footprint if they account for all of the energy they use and all of the embedded energy in every product they use or consume.

2. Explain that you would like your students to think about what they learned in the first activity and consider actions they can take to reduce their energy footprints when it comes to the water they drink. Depending on your school facility and policies, you may discuss ideas such as banning bottled water from your school campus and vending machines, providing reusable beverage containers to students, or allowing students to take more frequent water breaks to use drinking fountains. See if students can come up with any other creative but realistic solutions.

3. In class or as a homework assignment, ask students to make a list of reasons for and against these actions. These can be based on the embedded energy activity and/or students can conduct research or be creative to come up with additional ideas. Then, have them consider all of these arguments before writing a paragraph explaining their position and their reasons for it.

4. After choosing the drinking water solution that could be best implemented at your school, divide the class into two groups based on whether they agree with the proposed solution or not. Allow each group to share their reasoning and clarify their arguments. Feel free to make suggestions if either side has missed an important argument.

5. Hold an informal debate. Allow students from each side to explain their rationale. Give each side the opportunity to ask questions of those on the opposing side, and allow for discussion and debate in response to each question. Be sure students consider perspectives of multiple people, including students, teachers, faculty, administrators, facilities staff, etc. and arguments they may have in favor or against such action.

6. Have a final vote on whether or not to take action on implementing a new policy at your school. Let students know that they do NOT have to vote for the side they represented in the debate if the debate changed their mind.

7. If your students feel strongly about taking action, have a discussion about how to best express this to the school community or to school officials. The next activity invites students to write editorials for the school newspaper explaining their opinions.

 

Wrap-Up: Write an Op Ed for Your School Newspaper

1. Explain that an ‘op ed’ is a page of special features usually opposite the editorial page of a newspaper. Op eds also refer to all of the features on that page.[4] ‘Op ed’ stands for “opposite the editorial page” because this is where it is located in a newspaper. This is a space for the readers and general public expresses opinions.

2. Explain that you would like each of them to write an op ed piece for the school newspaper expressing their opinion on reducing the energy footprint of water and beverages consumed at school. They can choose to represent a specific action or write about several. They may also choose to write against an action. In any case, they should be sure to include thoughtful and persuasive evidence considering all sides of the issues and the perspectives of others.

3. Exhibit the op ed pieces in a prominent hallway or on the school website for other members of the school community to read. Select several of the strongest samples for submission to your school newspaper (or local paper!). You might also consider having your students decide which ones should be submitted.

 

Extension: Calculate the Cost of Drinking Water in Your Municipality

  1. As a class or as an additional assignment for students, research the drinking water municipality for your area. Who provides, collects, treats, and transports the water in your area? You may want to use or refer to the Where Does Your Drinking Water Come From? lesson plan in this unit.
  2. Bring in a typical water utility bill. Compare the cost of tap water at your home with an equal amount of bottled water. Estimates are fine.
  3. Instead, or in addition, find data online or contact your municipality to find out how much your community spends on drinking water. Online resources include:

·        “Ground Water & Drinking Water FAQs,” U.S. Environmental Protection Agency, http://www.epa.gov/ogwdw000/faq/faq.html#source.

o       This is a great place to start for answering Frequently Asked Questions on groundwater and drinking water. For more information on your drinking water you can also visit their question and answer database on this site or call the EPA's Safe Drinking Water Hotline at 1-800-426-4791.

·        Water Science for Schools, U.S. Geological Survey, http://ga.water.usgs.gov/edu/wwvisit.html.

o       This site includes a step-by-step guide describing what happens at each stage of the water treatment process and how pollutants are removed to help keep our waterways clean.

·         “Local Drinking Water Information,” U.S. Environmental Protection Agency, http://www.epa.gov/safewater/dwinfo/index.html.

o       This site allows you to find data and contact information for your state drinking water program.   

·        “Standards and Risk Management,” Office of Ground Water and Drinking Water, U.S. Environmental Protection Agency, http://www.epa.gov/ogwdw000/standards.html.

o       Here you can find information on contamination and regulation of drinking water.

·        Watershed Assessment, Tracking & Environmental Results, U.S. Environmental Protection Agency, http://www.epa.gov/waters/.

o       This site unites water quality information from several independent and unconnected databases.

  • 4.  Convert this amount to cost per liter and compare to the numbers discussed in Activity Two section of this lesson.
  • 5.  How does your area compare to other communities in other regions? What factors might some of these differences in cost? How do these costs compare to general bottled water costs? What are some possible reasons for differences?

 

Extension: Calculate the Oil Consumed in Drink Bottles by Your Class in One Week

1. Ask students to record how many drink bottles (of any kind) they use in a week and their sizes. Pass out copies of Reproducible #2 – Record of Drink Bottles Used in a Week, and explain how to complete the sheet. It may be helpful to present examples of various sized bottles for student reference (355ml, 591ml, 1L and 2L).

2. Compile the results of all students and calculate how much oil was consumed simply to provide the drink bottles that they used in a week. (Remember to divide the total number of milliliters by 1000 to get a total number of liters.)

3. Consider filling that number of liter bottles with “oil” and displaying them with a sign in a prominent location in your school for others to see.

4. Talk to students about what other products they use that have energy embedded in their lifecycle (nearly everything does). Have students choose an object, research its lifecycle, and give a report or presentation in class.

 

Extension: Calculate Your Water Footprint

  1. In addition to energy footprints, many products also have water footprints, using substantial amounts of water to produce and transport. Have students calculate their water footprints. The Water Footprint Calculator (found under “Your Footprint Calculator” at www.waterfootprint.org) is a great online tool that will allow your students to calculate their extended water footprints (equal to the water required to produce the goods and services they consume). They can also visit http://www.h20conserve.org/home.php?pd=index or www.epa.gov/watersense/calculate_your_water_savings.html.

 

CONCLUSION

As a result of this lesson, students will understand that every product they buy has embedded energy in it. Specifically, they will have mapped out and illustrated each step in the process of making bottled water that requires energy and learned that bottled water can take up to 2000 times the energy required to produce tap water! Students used what they learned to discuss and debate options at school or actions they could take to reduce their drinking water’s energy footprint. They also wrote an op ed piece expressing their opinion on this topic.

[1]Embedded Energy. Environment Australia: Department of the Environment and Heritage. Retrieved 14 March 2010 from http://buildlca.rmit.edu.au/Embodied_energy_definition.html.

[3]Data supplied by Vikas Singhal, Manager of Budget and Finance at the Army Corps of Engineers Washington Aqueduct. February 3, 2010.

[4]Op Ed. Merriam- Webster Online Dictionary. Retrieved 12 March 2010 from <http://www.merriam-webster.com/dictionary/op%20ed>.