I know this, one of the guys who used to be in my club was/is an engineer for some of the new dump sites in the US. I'm sure they never leak...
I work right next to one, actually the one right across from CC's building. They just keep building it higher & higher. I'm sure it never has run-off.
But... It does supply gas for the GM Lake Orion Plant.
I realize they have got better, but we are surrounded fresh water & they have plentiful open unused desolate area.