McConnell Dowell pleased to announce that Gisborne District Council has awarded the Stage Two of the upgrade of Gisborne Wastewater Treatment Plant to McConnell Dowell.

Located in New Zealand’s North Island, this project involves the construction of a secondary clarifier and tertiary treatment facilities to treat domestic wastewater after the existing biological trickling filter. This new infrastructure will be more resilient in the event of natural disasters and will improve water quality.

This is an exciting project for the McConnell Dowell team to continue to build on our extensive track record in wastewater plant construction throughout New Zealand, Pacific, Australia and South East Asia.

McConnell Dowell worked in collaboration with Gisborne District Council and designers BECA to ensure the project’s key requirements around performance and social outcomes were met within budget.

McConnell Dowell Managing Director for New Zealand and the Pacific Islands, Fraser Wyllie says; “We are excited to work for Gisborne District Council to deliver an upgraded and more resilient infrastructure which responds to the region’s growth”.

Stage two includes construction, installation and commissioning the following new processes:

  • New clarifier pump station to transfer the effluent from the biologically trickling filter (BTF) to the new clarifiers
  • Ground improvements including engineered rafts
  • Lamella type, secondary clarification to remove the gross solids from the effluent
  • Scum and sludge underdrain removal system
  • Disc-cloth type tertiary filtration system for effluent polishing prior to disinfection
  • An in-channel type, ultra-violet disinfection system
  • New screw presses for dewatering
  • New recycled effluent system which will be used to provide wash water for process related equipment
  • Civil works (pipelines, drainage, stormwater, stormwater treatment, pump station, chambers, roadways, hardstands etc)
  • Structural works (concrete pads, steelwork platforms etc)

The work will commence in early September 2021, with completion due in Mid-2022.