Tiwai landfill a toxic

‘‘Catastrophic’’ consequences of ‘‘extensive, irreversible’’ environmental damage and even loss of life are being forecast from sea-level rise breaching a landfill including toxic waste at the Tiwai Point aluminium smelter in Southland.

The smelter company rejects the findings, but engineers’ reports to the Treasury say it is ‘‘almost certain’’ the sea will swamp a landfill that contains 250 Olympic-sized pools of waste.

That report is looking a century ahead, but the smelter company’s owner, Rio Tinto, plans to leave the smelter in less than four years.

Talks on how to clean up the site foundered this month, with the Government protesting a lack of transparency by the company.

In the reports, a risk assessment on coastal inundation said there were no ‘‘existing controls’’ to deal with it.

‘‘Sea-level rise of 1 metre combined with erosion-generating storm surge events will cause an inland movement of the coastline by 100 metres within 100 years, eroding landfill ‘berms’ and releasing contaminants, causing extensive irreversible environmental damage and health impacts, with the potential to cause fatalities,’’ the report by consultants Aurecon said.

Before that happened, seawater would intrude underground, risking ‘‘potential health impacts to humans with the potential to cause loss of life’’.

Environment Minister David Parker told RNZ they were serious issues. But he remained ‘‘blind’’ on the extent of the contamination, despite the 170 pages of reports released under the Official Information Act; these went to Parker and the Treasury last September-October, and a second tranche of as-yet unreleased advice went to them last November.

The company pushed back, saying it had not seen the Treasury reports until RNZ sent them through on Tuesday.

New Zealand Aluminium Smelters (NZAS) chief executive Stew Hamilton said in a statement: ‘‘We are very concerned by what we believe are inaccurate assertions and conclusions made by this desktop study.’’

Their preliminary modelling showed ‘‘no impact’’ from sea-level rise on the landfill ‘‘within the next 100 to 200 years’’, he said.

Parker said the reports did not say ‘‘we’ve got immediate sea-level rise around the corner. It says that we’ve got a future problem.’’