What Happens to Cat Litter in the Landfill?

To help combat climate change, many eco-conscious households are taking steps to reduce the amount of waste they send to landfills. 

Oftentimes, however, our pets are a blindspot. After all, soiled cat litter can’t be repurposed, reused, or recycled.

But what exactly happens to cat litter when we send it to the landfill?

In the landfill, clay cat litter will remain in its current form indefinitely. Even biodegradable, plant-based litters will remain for many years thanks to the anaerobic conditions present in landfills.

Does cat litter decompose in a landfill?

To better understand what happens to cat litter in a landfill, it’s important to first learn a bit more about what’s needed for decomposition and how modern landfills are designed. 

What’s needed for decomposition?

Decomposition and biodegradation are hastened by three key elements — moisture, oxygen, and energy.

Lacking one or more of these elements, decomposition will be greatly slowed and, in some cases, nearly stopped completely.  

What happens in a landfill?

A common misunderstanding about landfills is that they’re a place to send garbage for decomposition. 

But many modern landfills are actually designed as a place to store trash — not to help it decompose.

Birds flying around at landfill

Older landfills were open dumps with plenty of moisture, oxygen, and energy, in the form of light and heat. 

In modern landfills, however, trash is tightly compacted, covered in plastic, and buried beneath a thick layer of dirt and clay — an anaerobic (oxygenless) environment with little to no source of energy.

Decomposition and biodegradation are greatly hampered. 

How long does it take for cat litter to decompose in a landfill?

Thanks to the anaerobic conditions present in many modern landfills, trash often does something closer to mummify than decompose.

Any cat litter sent to the landfill is likely to remain in something close to its current form for many years, with non-biodegradable litter, like clay and silica crystal litter, effectively remaining forever.

A bit of good news

On the bright side, recent innovations in landfill technology may help. At least when it comes to plant-based cat litter. 

Bioreactor and leachate recirculation technologies aim to manage moisture levels in landfills, stimulating the microorganisms responsible for decomposition and reducing the methane gas emissions contributing to global warming.

How much does biodegradable litter help?

Quite a bit. 

Pile of wood pellet cat litter with wood logs

While it’s true that even biodegradable cat litter will remain in its current state for many years in a landfill, it’s still a much more eco-friendly alternative than clay litter.

Bentonite clay is a non-renewable resource, harvested through the damaging process of strip mining, which irreversibly scars landscapes and pollutes waterways. 

Plant-based litters, on the other hand, are made of renewable resources and are rarely harvested for the sole purpose of making litter.

Recycled paper, wood scraps, and walnut shells, to name a few, are repurposed scraps of other industries that would otherwise go to waste. 

Plant-based litter also opens up the door for alternative, environmentally friendly disposal methods — burying and composting

Final thoughts 

Clay and silica crystal litters aren’t biodegradable and will remain in their current form indefinitely, whether sent to the landfill or not. Biodegradable, plant-based cat litter will typically decompose in six months to a year outside of landfills, but will take much longer in the typical anaerobic conditions of a modern landfill.

To help reduce your cat’s carbon pawprint, use a plant-based cat litter, avoid using plastic to bag litter, and compost or bury your litter whenever possible.

About Matthew Alexander

Matthew lives in Maryland with his two cats, Puff and Pancho. He’s been caring for and fostering cats with various special needs for more than fifteen years. He hopes to pass some of the insight and knowledge that he’s gained on to the readers of Pawmore.