Are You Having Garbage for Lunch?
A School Trash Audit Activity

Lesson Summary
Over a two week period, students record the "garbage" that is left after eating their lunches. Students determine the composition of their lunch leftovers, weigh them, and develop strategies to reduce the amount of waste.

Key Concept
Over-packaging, disposable products, uneaten food, and not reusing or recycling can all contribute to a lunch full of garbage. Little things such as using a reusable lunch box, or recycling soda cans, or composting food waste can become part of a daily routine, greatly reducing the amount of garbage that is landfill bound. Students take responsibility by analyzing their own lunches and developing ideas on how to make less garbage and shop with the environment in mind.

After completing the lunch waste audit, students will be able to:

  1. identify components of the "garbage" in their lunches
  2. recognize that everyone makes garbage and that a little garbage made each day adds up
  3. determine alternatives to making landfill bound garbage
  4. recognize that a little effort adds up to a big reduction in the amount of garbage made
  5. apply waste reduction techniques to their lunch waste
Teacher Preparation:
Find out the recycling protocol at your school. The recyclables will need to be separated and stored as prescribed by your school's recycling policy. If your school does not have recycling on site, find out if students, parents, faculty, or neighborhood youth groups are interested in collecting your class' recyclables.

Find out the composting protocol at your school for the food waste that is collected in the experiment. Many science classrooms set up worm bins and some schools have extensive composting on site. Some students may compost at home and may be willing to take the vegetable waste home with them.


  1. On the first day of the activity, prepare students by telling them that they must bring everything left over from their lunch back to class. This includes all leftover food, paper bags, beverage containers, and other packaging materials as well as lunch boxes, eating utensils, and napkins.

  2. Once students return to class after lunch, hand out the worksheet. Have students individually complete the attached worksheets. (See sample worksheet)

  3. After individual items have been recorded and categorized, instruct students to form small groups. Ask students to sort their lunch items and place them in the appropriate plastic container (recycle, landfill, or compost). Explain that there is not a "reuse" container because if the students plan to reuse something then they need to keep it and take it home.

  4. Have each group record the total number of items that were reused, recycled, composted, and landfilled on the bottom portion of the worksheet.

  5. Have each group weigh the full containers and record the weight on the worksheet. (Remember: to find only the weight of the garbage, students will have to subtract the empty container's weight from the full container's weight). Have students record the weight of the contents on the bottom of the worksheet.

  6. Have students record their group findings on the board and add up all the figures. The class total for the day can be recorded on the worksheets.

  7. The container with recycleables needs to be separated and stored as prescribed by your school's recycling policy (see teacher preparation). Ask one person in each group to be in charge of the recycling.

  8. The container with the compostable material needs to be composted in class or taken home by a student/teacher who composts (see teacher preparation). If this is not an option, explain to students that this material is compostable, but since there are no compost facilities it will go to the landfill.

  9. Repeat this activity daily for one week. At the end of the first week, have students compare the results of each day to see if there is any change. As a class, discuss the findings and compare the class data over the week. What trends do you observe, if any?
The procedure of week two is the same as week one, but with one additional step.

  1. When students are completing their worksheets individually, have them complete the "Next Time Will Try" column with alternatives to their current action. This will help students think about the first "R"--reduce --in the waste hierarchy (Reduce, Reuse, Recycle).

  2. At the end of the two week period, have students compare the data from week one from week two. Are there any differences? Any trends? How do their predictions measure up against the results?
Let students brainstorm in groups about waste reduction and ways that they can make less garbage at school and at home. Have students give group presentations to the class and develop a list of tips they can be take home to parents.

Student Worksheet -- WEEK ONE(Sample)
Lunch Item Reuse Recycle Compost Landfill
torn plastic grocery bag0001
apple core 0010
plastic sandwich bags3000
soda can0100
paper napkin0010
yogurt cup 0001
plastic spoon1000
GROUP weight of empty container    
GROUP weight of full container    
GROUP weight of contents    
CLASS weight of contents    

Student Worksheet -- WEEK TWO(Sample)
Lunch Item Reuse Recycle Compost Landfill Next Time I Will Try
brown paper bag1000using lunch box
soda can 0100using thermos
uneaten bag of carrots0001saving for later
soda can0100NA
paper napkin0010reusable towel
yogurt cup 0001recycling
plastic spoon1000NA
GROUP weight of empty container    
GROUP weight of full container    
GROUP weight of contents    
CLASS weight of contents    

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