I find the same socialist worker party types who were full of keeping the coal mines I worked down are now all of a sudden environmentalists.

Raging against the machine. It's rather popular. Write a song about it.

As raggytash mentions, surface buildings are minimal. Subsidence isn't an issue in hilly areas. Basalt is a bugger to shift even if you want to.

Jobs, needed potash, local infrastructure.

Not all proposals are good of course. But not all are bad either.

There again, I don't wear sandals.