Helensville WWTP upgrade

  • Client: Watercare
  • Year: 2013

SEL was appointed as the main contractor, which covered all Civil, all Electrical, all SCADA and PLC work.  This plant was a live plant and had to be kept live during the entire course of the project. The project also had considerable environmental implications because the settling pond and treatment plant is on the Kaipara river. Extra care was required to protect the environment during construction works, especially when diverting the flow of the rising main pipework.


The contract consisted of installing 5x new mechanical Aerators into the settling pond which were anchored from, and have access from, the embankment of the pond. The main challenge for this particular part of the contract was excavating the embankment for the anchoring blocks, which were below the pond water level, without compromising the pond dam wall in any way.   SEL also procured and installed 2x neoprene rubber membrane baffle walls across the pond, which were anchored from the shore, to divert flows in the pond allowing for more contact time between the wastewater to oxygen.   A new Operator building was also constructed which housed the new switchboard and PLC.

Helensville WWTP upgrade - Gallery