Te Whare Wai Para Nuku

Customer:  Wellington City Council

Contract: Construct 

Location:  Moa Point, Wellington

Water & Wastewater Solutions New Zealand & Pacific Islands

Fast Facts: 

  • We need to build two 16m high concrete digestor tanks
  • a 26-metre-tall steel process building for mechanical equipment 
  • lay 10 km of new process pipework
  • connect more than 20 different mechanical systems 
  • procure and install 2,100 valves 
  • linked by 52 km of electrical cabling. 

McConnell Dowell and joint venture partner HEB are building the Wellington Sludge Minimisation Project, also known as the Te Whare Wai Para Nuku for Wellington City Council.

Te Āti Awa Taranaki Whānui gifted the project its new name, which encompasses the mana of the facility, the cutting-edge processes it will perform, and the spiritual transition of the wastewater from tapu (restricted or sacred) to noa (free from tapu).

A world-class facility, the new plant will be the first in Aotearoa (New Zealand) to use thermal hydrolysis – heating and drying under pressure - to sterilise, reduce the volume of the sludge, and make it more biodegradable. Biogas, produced by bacteria breaking down the waste, will also be captured and used to help power the facility, further reducing the plant's carbon footprint.

The sustainability benefits include:

  • reducing sludge volumes by up to 80%
  • reducing carbon emissions from the treatment and processing process by 60%
  • minimising the amount of waste going to landfill
  • producing a low-odour stabilised (inert) product
  • treating the sludge so it can be used productively, as a soil conditioner, fertiliser, and fuel for industrial heat.

Construction is now underway with completion expected in late 2026.  

Check out the project's progress in our monthly newsletter:

Project Update: March 2025

Project Update: April 2025

 Project Update May 2025

Project Update June 2025

Project Update July 2025

  

 Latest Progress on the project in the videos below

 

 Te Whare Wai Para Nuku - the story of the project's name

Te Āti Awa Taranaki Whānui gifted the project a name that speaks to the importance of the new plant - Te Whare Wai Para Nuku. The meaning of the name encompasses the mana of the facility, the cutting-edge processes it performs and the spiritual transition that the wastewater undergoes within the plant, changing it from from tapu (restricted or sacred) to noa (free from tapu). 

The name of the sludge minimisation facility refers to Te Whare being the facility itself, and how it safely holds high volumes of kene–biosolids, or sludge.

Wai Para describes the water left in the kene or sludge after it has been treated first in Te Whare Wai Tapu Noa (the wastewater treatment facility), before it flows to Te Whare Wai Para Nuku. This water is not safe to go directly back into Tangaroa, the sea.

Para is a word often used to mean waste. It refers to the tikanga of excess fibre discarded by kairaranga who weave and care for harakeke, or flax. The excess fibre from the weaving process is discarded in specific areas that don’t negatively affect Māori Kāinga, and then returned to the whenua or land so it can again become one with Papatūānuku.

In this context, para refers to the extracted kene from waimate (dead water, water deemed unsafe), like para is extracted from harakeke.

‘Nuku' speaks to how the treatment processes mimic natural decomposition processes and will use modern technology to enable wai para and kene to go from a state of being tapu to noa before being used beneficially. It (nuku) is also a reminder to everyone of the purpose of the plant, the ongoing improvement and the elimination of harmful waste.

 

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