I’ve heard, shipping a lot of garbage to China was quite common until the Chinese banned it. That was economically viable because China exports so much and many container ships would otherwise return empty to China.
I thought they didn't bother and just buried it if it wasn't profitable.
>GONZALEZ: Whoa. Oh, I've been doing that one wrong. So the city of Nogales went around to everyone's house this morning and picked up their recyclables. [...] And they brought them here. And where is all this going to go?
>GALLEGO: Trash.
>GONZALEZ: The recycling is going into the trash. I am watching pristine beer bottles and juice cartons and cardboard boxes get smushed into a pile of wet, gooey, dripping food waste and soggy diapers.
The point is to cheat. Say you recycle and ensure that there are enough links in the chain nobody can follow it to the end and prove the stuff you ship to China wasn't recycled. China did recycle some stuff, but most of it wasn't. China decided to stop participating in that scam though.
In my county, they are obliged by the contract to NOT bury the mixed recyclables. So they used to offload it to some companies that would then also promise not to bury them (pinky promise), and ship them to China. Contracts in China are then not so easy to follow and enforce and voila, problem is now somewhere else.
China, and other countries, put limits on such imports, as their recycling industries were not exactly environmentally friendly. Technically you can still import plastic waste into China, but with a very low contamination percentage that's hard to achieve.