Dispersal debate ongoing

Negotiations about the possible dispersal of treated sewage sludge on farms near Luggate is still ongoing between two landowners and Queenstown Lakes District Council representatives.

QLDC solid waste manager Stefan Borowy was questioned on Tuesday by members of the Wanaka Community Board, who wanted updates on the council's sludge-spreading proposal.

Board member Dick Kane wanted more information about whether the sludge would be hazardous, given it had killed worms during a processing trial conducted by a Cromwell worm farm operator.

Mr Borowy said the trial was conducted independently and without any input from the QLDC.

"We supplied the sludge, but we do not have any control over the trial whatsoever," he said.

Further research had been carried out by council staff, after the Otago Daily Times highlighted the fatal effects an introduced polymer was having on sludge-processing worms.

The polymer, introduced as a coagulate to firm up sloppy sewage sludge for transport requirements, breaks down when left exposed to the elements, Mr Borowy said.

A trial conducted in Palmerston North produced results which showed the polymer broke down after three days outside, he said.

Mr Borowy's research findings are disputed by Cromwell Wormworx operator Robbie Dick, who has told the ODT worms were still reluctant to process the sewage sludge despite it being exposed for up to eight days.

Mr Dick claims the artificial polymer is a harmful "inorganic" substance to his worms.

He has also raised concerns about the possible effect of the polymer if introduced to soil.

The QLDC will need to obtain resource consent before it can carry out a sludge-dispersal project.