Much of the elevated land on Nauru, 15 of its total land area of 21 square kilometres, has been rendered unusable by mining, but there have long been hopes that it can be restored, for farming and habitation.
Over the past two years preliminary work has been done by the Pacific Community on a project the Nauru Government said will be the biggest undertaken on the island.
A New Zealand engineering consultancy, Calibre Consulting, is now being brought in to consider the options that have been developed.
The head of the Nauru Rehabilitation Corporation, Peter Jacob, said they want to restore about 25 percent of the area, known as Topside, over the next 20 years.
He says the cost of the total restoration has been put at $US1,014 billion but that is nothing when spread over the planned 100 years the project is expected to stake.
Mr Jacob said his organisation will be transformed by the work to be done and he's encouraging young Nauruans to train in engineering and science, so they have the skills to fill the positions that will be created.