Anger over contaminated site botch-up

Residents near New Zealand's most contaminated site feel betrayed by a botched $12 million clean-up project.

They say the clean-up at Mapua, near Nelson, released dioxins into the air, possibly spread mercury through the site and contaminated the neighbouring estuary with copper.

Neighbours of the former Fruitgrowers Chemical Company site want to know what went wrong with the remedial work that took nearly four years and divided friends and neighbours.

The site has been earmarked for residential, commercial and recreational development but has still not been audited by the Ministry for the Environment.

Parliamentary Commissioner for the Environment Jan Wright said yesterday the containment of many of New Zealand's contaminated sites may be the best financial and environmental option, rather than trying to clean them up.

In its report on the "high-risk" clean-up process for the 5.5ha site in the middle of a residential area and next to an estuary Wright exposed a series of errors.

They included resource consent breaches, copper contamination of groundwater and the estuary, lack of action by the ministry to reduce groundwater contamination, organochlorine consent levels being exceeded, the potential existence of mercury contamination on the site being ignored and the Tasman District Council not enforcing consent conditions.

Neighbour Annette Walker said she felt betrayed by the mistakes revealed because she had trusted agencies to carry out the clean-up properly.

"The report raises huge questions," she said. "Why has the site still not been signed off and are the big heaps of soil remaining on the site still covering things up?"

Wright said reports from the Ministry of Health and the Department of Labour on the health effects of the project on workers and residents were still several months away.

Airborne dioxin contamination occurred between September 2004 and late 2005 when an emission scrubber-system on the new-technology process at the site was not working properly, releasing an unknown amount of contaminants, Wright said.

Initial trials of the technology had revealed the potential for dioxins to be produced by processing the contaminated soil, but it was decided this was an aberration and dioxins were not monitored, she said.

"Residents may have been exposed to dioxins from late 2004 and during 2005, but there is no way of knowing how much was emitted."

She said the site was now safe and most of the organochlorine chemicals had been destroyed.

Mercury-based pesticides were produced in the area now set aside for housing for 20 years and Wright was concerned thorough mercury sampling was not carried out.

The clean-up focused on organochlorine pesticides as mercury contamination was not seen as a priority, she said. "Either the mercury was dumped elsewhere or the sampling never found it."

It was a significant concern that future residential gardens could be developed on the potentially mercury-contaminated land as the mercury was likely to be in the top layer of returned processed soil, she said.

The shift of clean-up contractor Auckland-based Environmental Decontamination to using copper as an agent in its process in 2005 was not approved in the site consent, but 13 tonnes was eventually used, Wright said.