The Environment Minister is demanding answers after soil contaminated with lead was dumped at a public tip in the Wellington region.
The Greater Wellington Regional Council was conducting a $14 million clean-up of Waiwhetu Stream, known to be one of the most contaminated waterways in New Zealand, to remove decades of heavy metals and toxic sludge.
Two truckloads of contaminated soil was dumped at the tip in the Lower Hutt suburb of Wainuiomata in October.
When residents originally complained to councillors, they were promised the material at the tip was perfectly safe. However, tests showed lead levels in the soil were twice the safe limit.
The regional council on Tuesday revealed a project manager in charge of the clean-up was aware that toxic soil had been dumped, but failed to inform councillors, senior managers or residents.
Council chief executive Dave Benham says at a public meeting, the project manager heard regional councillors mistakenly reassure Wainuiomata residents, but did not speak up.
"At that meeting the project manager then should have, in my view, at least informed the community of the issue. He did not, he tells me, on the basis that he thought the (toxic) material had been removed.
"Senior management should have been informed, councillors should have been informed and the material should have been removed earlier once it became known."
Mr Benham told Checkpoint on Tuesday the manager has been removed from the project and will face disciplinary action.
The Wainuiomata Community Board says the toxic loads are still at the Waiu Street tip and fears further contamination as lead dust is being blown about by high winds.
The regional council says it will begin moving the contaminated soil and up to 13 truckloads of surrounding earth to a more secure site at Silverstream in Upper Hutt on Wednesday.
The Ministry for the Environment is funding part of the clean-up and the minister, Nick Smith, has called for a report into the matter.
Dr Smith says he takes the view that when public agencies breach the law and the Resource Management Act, they have the same duty of care as anyone else.
Hutt South MP Trevor Mallard says the regional council has made a serious mistake and he will not rest until the contaminated soil is disposed of properly.