Waipa District Council is working to resolve issues with Cambridge’s wastewater treatment plant, which does not currently comply with some of its consent conditions.
This week’s Environment Waikato Regulatory Committee meeting heard that Waipa District Council is implementing changes to the operation of the Cambridge Wastewater Plant to meet all its consent requirements.
Environment Waikato Resource Officer Peter Stevens outlined recent progress with three wastewater treatment plants that Waipa District Council operates.
Templeview’s wastewater is now piped to Hamilton City Council’s wastewater treatment plant and inflows to the Templeview plant had ceased, with the plant to be de-commissioned, he said.
A new resource consent was granted for the Te Awamutu plant, with upgrades incorporated through conditions requiring progressive improvements to the discharge quality. Since the new plant was commissioned late last year the quality of the discharge had performed well within its consent requirements.
However the Cambridge plant had been struggling to meet resource consent discharge standards. The consent limits on dissolved inorganic nitrogen concentrations had been exceeded. A similar problem with dissolved reactive phosphorous concentrations has now been fixed.
Waipa District Council representative Tim Harty said the council was implementing a management plan, prioritising plant improvements and investigating long-term management options for biosolids.
“We are committed to getting it sorted out one change at a time,” he said.
Waipa District Council had investigated the sources of inputs to the plant, which included effluent from a nearby piggery, effluent from an Inghams chicken processing factory and septic tank discharges.
The piggery had been shock loading the plant with high strength waste, affecting its performance. The trade waste agreement expires at the end of next year and the owner had been advised that it would not be renewed. Once the input stops the concentration of inorganic nitrogen is expected to significantly reduce.
The council had also restricted the times that septic tankers could discharge into the plant so that staff could monitor the discharges.
It had also investigated measures to improve performance of the plant, including de-sludging the anaerobic pond and installation of a new aerator.
Chairman Jim Howland asked that the Committee be kept up to date with progress.