House training cats is easy. Most will use a litter box instinctively before they’re a month old. But what’s the environmental cost of the litter they’ll need over the years?

Some new cat box fillers are marketed as more sustainable that conventional litters, including a few that claim to be flushable or compostable. (Spoiler: They’re not.) Others are made from agricultural leftovers like walnut shells.

We’ve dug deep to see which ones are good for your kitty and the environment. Here’s what we learned.

Conventional cat litter is made from bentonite, a remarkably absorbent clay. Much of the world’s supply comes from strip mines in the Western United States, especially Wyoming.

Strip mining, in which machines remove the top layers of soil over a wide area to reach a mineral instead of tunneling, can destroy ecosystems, cause erosion and pollute water.

Federal and state laws require bentonite mining operations to restore land they’ve excavated. But many bentonite deposits occur underneath sagebrush grasslands, a scrubby yet biologically diverse habitat that supports Western species like pronghorn and greater sage grouse.

We are having trouble retrieving the article content.

Please enable JavaScript in your browser settings.


Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.


Thank you for your patience while we verify access.

Already a subscriber? Log in.

Want all of The Times? Subscribe.