I’d suspect it ain’t just trees and “green” stuff. The trailers going in there may look like trees and whatnot, but there’s no telling what kind of junk is intermingled with it.

A dump truck full of limbs can hide all sorts of tires, batteries, paint, or whatever other kind of liquid you pour into it. I’m not saying every load is like that, but they can’t possibly make sure every square foot that of that trash getting dumped in there is just as advertised.