Quick Read

• Without access to air or sunlight, trash in a landfill breaks down very slowly.
• Materials like plastics emit toxic chemicals over hundreds of years as they decompose.
• Landfills take precautions to prevent environmental damage from these harmful by-products, but they don’t always work.
• We must decrease the amount of stuff we throw away to lessen our dependence on landfills.

Wait, Doesn’t Everything Just Break Down In A Landfill?

Do you ever stop to think about what happens to your trash after you throw it away? Sure, a truck picks it up and takes it to the landfill – we all know that. But what happens after that?

While we might like to think that waste just disappears into a magical hole where it’s obliterated completely, the truth is a lot less appealing. If you’re ready to learn the dirty truth about where your trash goes, then read on; we’re going to take a quick look at what actually happens to your garbage once it reaches the landfill.

Where does our trash go?

Once your trash reaches the landfill, it does go into a big hole. Unfortunately, it’s not a magical one, but it is more than just your average, everyday hole. Modern landfills have been specifically designed to keep trash and the by-products of its break down contained.    

If you look at a cross-section of a landfill, you can see the various layers of protection that were put in place before trash even entered the picture. These protective measures include a clay and/or plastic liner to prevent runoff from entering the environment, a system to capture or vent pent-up methane gas, groundwater monitoring equipment to test for potential contaminants, and pipes to collect leachate (a highly toxic liquid by-product of decomposing trash.)

When your trash arrives at the landfill, it’s dumped into an open area called a “cell” then compacted to take up less space. In most modern landfills, only one cell is open at a time. At the end of the day, when all the trash has been added and compacted, a layer of dirt is spread over the top to contain debris, discourage pests, and minimize odors.

How long does it take for my trash to break down?

Now that your trash is tucked into its dark, dirty new home, you’d think the decomposition process would start pretty quickly, right? Unfortunately, that belief is wrong. Landfills aren’t designed to promote decomposition; in fact, conditions discourage it.

Since trash buried beneath the ground has no access to sunlight or oxygen, it takes a very long time for it to decompose. How long? Well, it depends upon the material. Paper waste breaks down the fastest, requiring only 2-6 weeks. Food waste takes a bit longer; it’ll decompose somewhere between 6 months to 2 years.

The material that takes the longest to decompose by far is glass. When added to a landfill, it can take glass not hundreds, not thousands, but millions of years to decompose. That’s why you should recycle every bit of glass that you possibly can; glass can be recycled over and over again in a closed loop without losing its integrity.  

While it’s important to recycle glass instead of pitching it, keeping plastic out of the landfill is even more vital. Why? Because glass doesn’t discharge any harmful components as it decomposes while plastic releases an abundance of toxic chemicals.

Not only does plastic release toxic chemicals as it degrades, it does so slowly, over a period of hundreds of years. Items like plastic toothbrushes, cups, and coffee pods can take up to 500 years to decompose. Even a thin plastic bag can require 20 years or more to completely break down.

What effect do landfills have on the environment?

While those who design landfills put precautions in place to limit environmental damage, no system is perfect. There are still many negative consequences to the use of landfills.

One of the biggest impacts is the amount of methane gas released by landfills. Methane gas is one of the most potent greenhouse gasses in existence and a huge contributor to climate change. Methane is generated in landfills as organic materials decompose. Modern landfills have pipes in place to either vent this gas or collect it for later use but even with collection systems in place, not all methane is contained.

Another issue with landfills is that the liners meant to contain runoff have been known to leak. Remember that leachate we talked about before – the toxic liquid by-product of decomposing trash? When landfill liners fail, that stuff gets into the ground and contaminates nearby water sources, which can have a devastating effect on the ecosystem.

And those are just a couple of the most destructive effects of landfills. There are many others, including the loss of natural habitat when creating landfills, a higher risk of congenital malformities for those who live nearby, and emissions of carbon dioxide and other elements that contribute to climate change.

That sounds terrible! How can we stop filling up landfills?

No situation is ever hopeless; we can all take steps to reduce our dependence upon landfills, such as:

• Be more willing to eat leftovers instead of throwing food away.
• If you simply can’t stomach leftovers, compost your food scraps instead of discarding them.
• Don’t throw items away; sell, donate, or upcycle them instead.
• Recycle everything you possibly can, especially glass, aluminum cans, and plastic.
• Better yet, stop purchasing single-use plastics altogether and find suitable alternatives.
• Look for other ways to reduce plastic usage like buying in bulk to reduce packaging, using a canvas grocery bag instead of plastic, drinking out of a glass or stainless-steel tumbler instead of a plastic bottle, etc.  

With a little time and effort, you can cut back on the amount of waste you produce and keep all that unnecessary stuff out of the landfill.