What's the best way to make sure that plastics are buried in landfills?

Most plastics aren't being recycled and it's unlikely that they ever will.

A big chuck of them are being dumped anywhere that's cheap. In some countries it's cheaper to dump waste in a river or directly in the ocean. We need to stop this.

How would you design a system that guaranties all trash ends up in a proper landfill? Remember, people don't want to spend money on it. So the costs have to be part of the overall plastic life cycle not just the end.