As evacuated residents were allowed to return home last night, Ian Davidson-Watts told a media conference ammonia levels were "way below" what the council had expected to find inside the Mataura paper mill, where the toxic material is stored.
Residents of the town were evacuated on Wednesday amid fears of rising floodwaters entering the old mill and mixing with the premix — the dross from New Zealand Aluminium Smelters’ Tiwai Point smelter — and generating poisonous ammonia gas.
“We’ve had some good news in relation to the ouvea premix — there’s been no significant floodwater in there," Mr Davidson-Watts said.
An inspection of the building by Gore District Council staff and Fire and Emergency New Zealand teams yesterday found it was structurally sound and dry, and fears the toxic ouvea premix would enter the environment were unfounded.
Mayor Tracey Hicks said the ammonia leak levels indicated six parts per million inside the mill and one part per million outside the building.
He understood levels would need to be ‘’well into the 20s" in order to injure the community’s health.
The council believed the flood defence and the procedures that were in place before the flood had kept the area from putting the community’s health at risk.
Alliance Group’s Mataura plant had also been “checked out" by various response teams and any danger it could have caused was ruled out.
Earlier yesterday, residents were still expressing their concern about the premix, and that it had been the reason they were evacuated.
They told media they had warned the council this would happen and felt they should not be made to live with the risk.
Mr Hicks acknowledged residents’ frustrations and apologised that the council had not "been able to get information to residents as quickly as we would have liked".
He said it was a large challenge physically and financially, but council staff were working with “key groups" to ensure the mill’s safety in the future.
Council chief executive Steve Parry confirmed that work was happening "fast".
All Mataura residents, who were evacuated to Edendale, were expected to be back in their homes by this morning.
