The clean-up of a badly polluted Wellington stream has created a second clean-up operation - at the landfill where the stream's toxic sludge was dumped.
Greater Wellington Regional Council officials have apologised to Wainuiomata residents after the highly toxic sludge from Lower Hutt's Waiwhetu Stream was accidentally dumped at a landfill in their suburb.
The sludge is contaminated with twice the safe level of lead.
Officials told the Dominion Post they had not realised the material was high in lead and the dumping was the result of a mix-up.
They deny there was any "cover-up" over the dumping and now face the task of removing 15 truckloads of material from the Waiu St site.
Local MP Trevor Mallard described the council's actions as "almost unbelievable". "The idea the council could ... not understand that it was polluted when they dump it beggars belief," he says.
Residents were assured the material was not contaminated, at a public meeting on November 27.
However, after concerns were raised, sampling revealed lead levels of 400 parts per million - twice the safe limit, and high enough to harm the environment.
Officials could not be sure there was no risk to human health, said council chief executive David Benham said.
"So we are taking a precautionary approach and removing the material."
It will be taken to the Hutt Valley's Silverstream landfill which is set up to take contaminated waste.
A $6.5 million project to clean up the stream - considered one of New Zealand's most polluted waterways - began in July.
An Environment Ministry spokeswoman said the ministry could not prosecute councils.
