Wanaka's $21 million wastewater disposal system, Project Pure, is operating again after its designer and builder addressed mechanical problems that emerged during the Christmas and New Year period, the Wanaka Community Board has been was told.
United Group Ltd secured the contracts to design, build and operate the treatment plant for two years.
Fulton Hogan won the QLDC contracts for the land disposal field and reticulation.
The system was commissioned in November and failed in late January, causing a two-tonne escape of treated waste into the dispersal fields.
Queenstown Lakes District Council water services manager Gary McGraw told the board the breakdowns were being remedied by the design-build contractor.
The adequacy of the design, construction and spares was being reviewed and investiga-tions were ongoing, Mr McGraw said.
The plant malfunction, described as "multiple concurrent failures", created a block in the disposal field and the treatment ponds at Wanaka and Albert Town were reinstated to handle the waste water during repairs.
The ponds were now "off-line" again.
Mr McGraw said a decanter failed and dropped to the bottom of the sludge in the new treatment plant at Wanaka Airport.
It had to be dug out and water-blasted.
Water jet pointers would be put on each line into the plant so water could be put through them in reverse direction to clean them out.
Fine mesh screens have also been put around the pumps in the back of the plant.
Those pumps send waste to the ultra-violet treatment unit and the disposal field.
The screens would be a "last stop effort".
Cr Leigh Overton sought and obtained an assurance from Mr McGraw it would "be impossible for an identical situation to occur".
Meanwhile, Queenstown Lakes waste water manager Martin O'Malley was preparing an information sheet for the board and the public on Project Pure, board chairman Lyal Cocks said.
Deputy mayor John Wilson said he was concerned the full financial impact on rates from Project Pure would not be felt by ratepayers until the next financial year and it was important the public did not forget the reasons for their investment.
The QLDC and its contractors will operate and maintain the treatment plant from 2010.
