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What Are Landfills and How Do They Work?

landfillYou have just finished your meal at a fast food restaurant and you throw your uneaten food, food wrappers, drink cup, utensils and napkins into the trash can. You don’t think aboutthat waste again. On trash pickup day in your neighborhood,you push your can out tothe curb, and workers dump the contents into a big truck and haul itaway. You don’t have to think about that waste again, either But maybe you have wondered, as you watch the trash truck pull away, just where that garbage ends up.

Americans make about four pounds of trashper day per person. This is almost twice as much trash per person as most other major countries.

What Happens to this Trash?

Ideally we recycle and reuse as much as possible. If trash is not recycled or reused it is buried in landfills.

What is a Landfill?

Landfills are not just mountains of trash – they aim to keep the community as safe as possible from the harm that can be caused when the garbage rots, or “decomposes.”

Landfills bury the trash so it will be kept dry and will not be in contact with air. Under these conditions, trash will not decompose much. When trash doesn’t decompose, it stays buried in the ground for a long, long, time.

Parts of a Landfill

landfill diagramThe basic parts of a landfill, as described below:

  • Bottom liner system – separates trash and “leachate” (leech-it) from groundwater. Leachate is like “garbage juice” – water that is made when garbage rots and when water falls on the landfill.
  • Cells (old and new) – spaces where the trash is stored within the landfill
  • Storm water drainage system – collects rain water that falls on the landfill
  • Leachate collection system – collects water that has drained through the landfill itself and contains pollution.
  • Methane collection system – collects methane gas that is formed when garbage rots.
  • Covering or cap – seals off the top of the landfill