Rio Tinto remains committed to Southland premix removal

Wednesday, 6 May 2020

New Zealand Aluminium Smelter chief executive Stewart Hamilton says the company is committed to the removal of ouvea premix from Southland.

Aluminium manufacturer Rio Tinto does not own a hazardous substance being stored in Southland warehouses, but the company remains committed to its removal despite not being in a position to store the product at Tiwai Point, New Zealand Aluminium Smelter chief executive says.

Stewart Hamilton was responding to a letter from Environment Minister David Parker, where Parker said he was considering legal action against the owner of the Tiwai Point aluminium smelter over its failure to deal with its hazardous waste.

Ouvea premix gives off ammonia gas when it is wet, and the Mataura building housing it was threatened by floodwaters in February.

The potential of an environmental disaster prompted Gore District Council chief executive Steve Parry to strike a deal for the premix to be fast-tracked from Mataura, but Rio Tinto pulled out of the deal.

* Environment Minister David Parker pens scathing letter to Rio Tinto

* Rio Tinto says 'nonsense' in electricity code a barrier to saving Tiwai Point smelter

Environment Minister David Parker is considering legal action against the owner of the Tiwai Point aluminium smelter over its failure to deal with its hazardous waste.

* Ouvea premix will still be moved if the Tiwai smelter closes

That prompted Parker to write a scathing letter to the aluminium producer, urging it to take responsibility for the class six hazardous substance.

Hamilton's letter of response was released to Stuff under the Official Information Act.

In the letter, Hamilton says the company ''remains committed towards working towards a sustainable solution for Southland and the people of Mataura, and that the ouvea premix is removed as soon as possible.''

He says there are no additional measures available in New Zealand Aluminium Smelter's control that would speed up the removal of the ouvea premix and ensure its safe processing.

NZAS was not able to temporarily store the ouvea premix at its Tiwai Point site, Hamilton's letter says. This was because any potential facilities would require significant remediation, causing significant delays, additional significant costs, and related legal issues, it says. NZAS had provided suggestions of more appropriate storage sites and the costs of those.

The company was unable to stop processing aluminium dross to process ouvea premix instead because they were two different materials and the premix needed to be treated differently, Hamilton said.

The company had made the Government aware of its suggestion of other potential users of the premix, such as cement manufacturers, Hamilton says in the letter.

About 25,000 tonnes of ouvea premix was left in five Southland warehouses, including the former paper mill building at Mataura, when Taha Asia Pacific went into receivership in 2016. It had a contract with the smelter to use aluminium dross to produce fertilizer, but the company's contract was not renewed.

In the letter, Hamilton addresses the company's business relationship with Taha, saying ti only became aware of ''significant compliance issues'' relating to the handling of the ouvea premix material towards the end of its five year contract.

Under a deal struck between interested parties in 2019, Australian-based company Inalco Processing Ltd will see the removal of 22,000 tonnes of the substance from sites in Mataura and Invercargill during the next six years. NZAS has pledged $1.75m towards the deal.