How Long Does Trash Last?

Age group: 11-15

This page provides you with a snapshot of this activity that looks more deeply at what happens to the stuff you throw away. Find out how long things take to break down in a landfill, and what speeds up or slows down the process. Lots of stuff we throw away lasts a very long time and can take many generations to decompose. Test your skills and knowledge and compete against each other to figure out how long certain things take to break down.

We recommend that you use the ‘Introduction to Solid Waste’ activity before any of the other activities as it is a good starting point for students to learn about waste and provides a comprehensive overview of how waste is generated and its impacts on animals, the environment and us. If you have already done so and wish to continue to download the rest of this free activity please click on the download icon below. Enjoy!

  • Learn about the waste hierarchy and the best options to manage waste
  • Understand the difference between landfills and open dumps
  • Discover how long experts think it takes different types of waste to break down/decompose
  • Learn the factors involved in the breakdown/decomposition of waste in the environment and in landfills

Whole class

  • Handout for students (A3 printouts)
  • Teacher’s cheat sheet (A4 printout)
  • Pencils & erasers for students
  • Blackboard

1-2 class period(s). If needed, split the class between steps 4 and 5:

  • 1st class period steps 1 – 4 (approximately 45 minutes)
  • 2nd class period steps 5 – 6 (approximately 50 minutes)
Skills used:

Problem solving




You will need to make photocopies of the ‘handout for students’ so that each group in your class gets their own copy. Find the answers on your ‘teacher’s cheat sheet’.




1 Question round (10-15 minutes):

  • How many kilos of waste are produced in India every day? (Answer: over 532 million kilos)
  • What happens to all this waste?
  • Where does all this garbage go? (Answer: landfill, dumping, burning)
  • What do you think is the best option to deal with waste? (Answer: refer to the waste hierarchy below)

Allow students to come up with their own answers.




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Lesson plan (English)
Teacher’s cheat sheet (English)
Students Handout (English)
Lesson plan (Tamil)
Teacher’s cheat sheet (Tamil)
Students Handout (Tamil)