Rio Tinto is negotiating a mine closure agreement with traditional owners that is set to include compensation for infrastructure that is left behind deep in the earth after 37 years of taking rare coloured diamonds out of the ground in Western Australia’s East Kimberley.

The closure agreement with traditional owners is being worked on as Rio prepares to spend upwards of $578 million over at least five years rehabilitating the site of the now closed Argyle diamond mine.