TOKYO: Recycled Tokyo water may soon be carried to the Pilbara on otherwise empty iron ore freighters.

The move comes more than a century after British cast iron was used as ballast for wool ships bound for Australia.

Just as cast-iron lace balconies adorn Victorian-era terraces in Sydney and Melbourne, the recycled Japanese water could be used to wet down the iron ore dust in Pilbara ports.

Water is scarce and expensive in the arid Pilbara, and using the recycled Tokyo sewage for dust suppression and processing would save valuable local potable water.

Japan and Western Australia are poised to test the scheme, which has the potential to deliver millions of litres of water for reduced cost.

It is believed the large miners -- including Rio Tinto -- have been kept informed about the proposal.

About 25 per cent of the world's iron is exported through the Pilbara ports -- including Port Hedland, Dampier and Cape Lambert. Much of it is sent directly to Japan and each year, thousands of freighters return empty, other than the huge volume of water taken on as ballast to stabilise the ships.

The aim is to replace the ballast water, which in some bulk carriers can exceed five megalitres, with recycled water from the Tokyo area.

However, the first trial shipment is expected to involve transporting a smaller volume of recycled water in drums so any chemical changes in the water during transit can be studied.

West Australia's trade commissioner in Tokyo, Craig Peacock, said the idea had great potential. "It's still early days yet. The Japanese Infrastructure Ministry is undertaking a feasibility study," he said.

"We think it's a good idea, although there are various hurdles to overcome. The premise is great, and if it's feasible it will be great for the Pilbara.

"It would allow us to divert potable water and it's better than the ships going back empty."

Source: The Australian