NZ upgrades wastewater plant at Rotorua Lake to improve water quality

The Rotorua District Council (RDC) in New Zealand has upgraded its wastewater treatment plant in a project worth $8.5m.

The upgrade includes the commissioning of a new membrane bioreactor technology to improve the water quality of the Rotorua Lake.

RDC utilities operations manager Eric Cawte said that the membrane filtration removes the highest possible nutrients from sewage resulting in high water quality.

"With membrane filtration technology we’re able to remove very minute particles containing nitrogen and phosphorus, on top of the already successful biological removal process," said Cawte.

The upgraded treatment plant has been fully tested and is now operational, but fine-tuning is still underway to ensure highest possible levels of nutrient removal.

Once fully operational , the upgraded plant will reduce the dependence on the existing forest irrigation system for the removal of nitrogen from wastewater.

"This means that the forest irrigation system would be substantially less at the mercy of weather impacts and other natural factors beyond anyone’s control," Cawte added.

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Image: A new membrane filtration technology has been commissioned to remove nutrient nitrogen from water entering the Rotorua Lake. Photo: Entropy1963.