Environment Court proceedings on ouvea premix begins

Friday, 3 July 2020

The Mataura River flooded in February, threatening the ouvea premix being stored inside the former paper mill building at Mataura. The premix gives off ammonia gas if it gets wet.

The Environmental Defence Society is filing declaration proceedings in the Environment Court in Christchurch today concerning the storage of ouvea premix in the former paper mill building in Mataura.

The proceedings will determine whether the New Zealand Aluminium Smelter is responsible for the removal of the ouvea premix, a class-six hazardous substance which produces ammonia gas if it gets wet.

“It’s our contention that NZAS is responsible for the material and should be taking immediate steps to remove it promptly to a safe site,’’ EDS chief executive Gary Taylor said.

“We are concerned that if the stored ouvea premix gets wet, it produces ammonia gas which is toxic to humans. It can also harm aquatic life. There are residences nearby as well as a Te Kohanga Reo child care centre,” Taylor said.

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Ouvea premix is being removed from the former paper mill building at Mataura, but the Environment Court will determine whether it is the responsibility of New Zealand Aluminium Smelter to remove it.

A decision on the proceedings was expected before the end of the year, he said.

New Zealand Aluminium Smelters Limited’s (NZAS) aluminium processing produces a by-product called dross, which can be subjected to an aluminium recovery and recycling process. One of the outputs of that process is ouvea premix, which has potential use in fertiliser manufacturing and steel production.

The smelter has already contributed $1.75 million to a six-year, $4m deal which will see all the premix moved to Tiwai Point, where it will be further processed by Inalco Processing Ltd. The premix at Mataura is being moved first because of the significant risks posed to both the environment and people by having the premix stored next to the Mataura River.

“If the ouvea premix gets wet, it could release ammonia gas at concentrations that could harm people. Whilst such an event is a low probability, it could have serious consequences. The timeframe for removal of the material, which is vague and uncertain, seems excessive given those risks.’’

NZAS is owned by Rio Tinto and Sumitomo Chemical Company.

“Rio Tinto does not have a good environmental track-record offshore, having recently destroyed a 45,000- year old Aboriginal cultural site in the Pilbara region in Western Australia. We wish to see a more responsible approach from NZAS to avoid adverse environmental impacts in this country.’’

Taylor said the backstory to the matter is complex, with NZAS having contracted out processing and recycling of the ouvea premix to a company that went into liquidation.

“Our declaration proceedings ask the Environment Court to rule on whether NZAS can contract itself out of legal responsibilities to avoid, remedy or mitigate adverse effects, or potential adverse effects, under the Resource Management Act.’’

The company that owned the ouvea premix was Taha Asia Pacific, which went into liquidation in 2016, leaving 10,000 tonnes of the substance in the Mataura building and more in other buildings in Invercargill and Awarua. In December 2017 liquidators formally disclaimed the premix, leaving the Government and local councils to deal with it.

The EDS’s Environment Court proceedings only involved the ouvea premix at Mataura, which was threatened by floodwaters in February, sparking a civil defence emergency and the town to be evacuated.

“The EDS proceedings are supported by affidavits that track the history of the matter and provide expert evidence on hydrology and chemistry. Our concern is that another flood event could inundate the warehouse storage facilities.’’

The Environmental Defence Society is a not-for-profit environmental organisation comprised of resource management professionals who are committed to improving environmental outcomes.