When you run out of space in a landfill you send some engineers and excavator operators out and dig a new one. The three reasons not to do that, as given by you

When you run out of space in a landfill you send some engineers and excavator operators out and dig a new one. The three reasons not to do that, as given by your article, are (paraphrasing) "permits and environmental regulations take a long time," "communities don't like it," and "it's bad for the environment." If the rubbish starts piling up, in the US or elsewhere, then all three of those issues are going to be quickly ignored in favour of digging another hole and adding the bare minimum of leachate collection.