News | 25 June 2024
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Sludge facility named Te Whare Wai Para Nuku

A te reo Māori name for the sludge minimisation facility being built at Moa Point has been formalised during the site blessing today.

Sludge minimisation facility under construction near Moa Point.

The name, Te Whare Wai Para Nuku, was gifted during a Matariki ceremony at the construction site this morning. 


Sludge minimisation facility project director Janet Molyneux says it has always been important that the way sludge is treated aligns with the values of mana whenua. 


“These names also point to the circular nature of what we’re going to achieve, with the treated sludge being able to be used in useful ways, rather than always buried in the landfill as it is now.


“It’s also great that the name supports and acknowledges how important what we are doing is for future generations to come.” 


Kaitohutohu of the sludge minimisation facility, Nate Rowe (Ngāti Mutunga, Ngāti Porou, Rongowhakaata, Te Whānau-a-Tauranga, Te Whānau-a-Taiaoa), researched tikanga that was traditionally practiced to make sure kene or sludge was safely managed, keeping both people and their taiao (environment) safe.


He says the name relates back to the values of mana whenua and the project. 


“The essence of the name is aspirational, nuku relates to one of the prime atua Papatuanuku. It’s aspirational because of the potential for the product to go back into the environment. 


“It’s a constantly aspirational thing for whoever is operating the facility, that they know the mana of the name, and they uphold that now and into the future.” 


To ground the name a ruruku or karakia has been introduced onsite to encapsulate the meaning of the name in a way that reminds everyone – from construction workers to members of our communities to the delivery teams and operators – why the facility and its technology is being built and why it is important for the future of our city.


Deputy Mayor Laurie Foon says Te Whare Wai Para Nuku will help protect the environment from the waste created by the city, and having such a meaningful name gifted helps to convey that important message.


“We’re honoured by the thought mana whenua has put into coming up with this name, they’ve really captured the spirit of what we’re trying to achieve by creating a solution for our sludge that is better for the environment, lowering emissions and helping us divert waste from landfill.” 


Te Whare Wai Para Nuku will break the link between the wastewater treatment process and landfill, removing the necessity to bury 40-50 tonnes of sludge in landfill waste each day. 

Staff working on site are given cultural inductions, and training on the meaning and narrative of the name and of the importance of the work being done. 


Janet says it was critical to make sure staff fully understand the names' meaning and significance. 


“Every kōrero we have makes us feel more connected as a group of people, connected to the why of the facility, and the value it will add.”


Te Whare Wai Para Nuku – The Sludge Minimisation Facility 



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, and flows to Te Whare Wai Para Nuku. This is the water that’s not safe to go back into Tangaroa, the sea. 


Para is a word often used in relation to waste. It refers to the tikanga of excess fibre that is discarded by kairaranga who weave and care for harakeke, 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 that is deemed unsafe), like para is extracted from harakeke. 


Nuku speaks to how the facility mimics natural decomposition processes and the technology of Te Whare Wai Para Nuku that enables wai para and kene to go from a state of being tapu to noa before being used in a beneficial way.


The use of nuku, is also used as a reminder to everyone of their commitment to the ongoing improvement and elimination of harmful waste. 


Key benefits:  

  • The facility will help us deliver on two critical targets the Council has set for reducing waste and carbon emissions in Wellington City. It will reduce carbon emissions created by the treatment and processing by up to 60 percent, and it will reduce the volume of sludge produced by up to 80 percent.  
  • Without it, we cannot reduce how much waste goes to landfill. Our current consents say that we must mix one part sludge with four parts waste. The existing consents at the Southern Landfill are due to expire in 2026, and a new sludge management solution is required to support future consents at the landfill.  
  • The new facility will enable resilient, sustainable and climate friendly waste management which can meet the needs of our rapidly growing city.  
  • Locating the facility at Moa Point rather than the landfill removes the need to pipe sludge 9km across the city through pressurised pipelines to the landfill. This will remove the risk associated with the pipelines, which failed in January 2020 resulting in a sludge being trucked between Moa Point and the landfill.   

How the facility will work:  

The heart of the new Moa Point sludge minimisation facility is the anaerobic digestion process, which mimics the natural decomposition process of waste, breaking down biodegradable matter in the sludge. As the sludge breaks down, it produces biogas which is captured and used to produce heat and electricity, which helps run the process. 

To make the anaerobic digestion process even more efficient and harness more energy from the sludge as it breaks down, the sludge is first put through thermal hydrolysis. This acts like a pressure cooker on the sludge, breaking down the sludge molecules so that the sludge becomes easier to digest in the anaerobic digesters. It also makes the sludge easier to dry. 

Because the end-product is inert, it can be easily stored or transported to other locations for disposal or potentially used productively. 

The facility will reuse the by-products from the WWTP and lysis-digestion process to provide the power and water needs for the sludge minimisation facility, reducing the need to draw from the Wellington city supply chain for these.

The levy:

  • From August 2024, a new levy will be introduced, as a separate payment to rates bills.  
  • The levy will cover the approximately $400 million required for the facility without affecting the funding for other important infrastructure and community projects.  
  • All Wellingtonians will pay the new levy, those connected to the wastewater treatment plants at Moa Point and Karori (most Wellington properties) will pay a higher levy than those not connected.  
  • The levy will begin in 2024 at a reduced level and gradually increase to the full amount in 2026/2027 when construction is completed. The finance raised will stay off Wellington City Council’s balance sheet, providing flexibility to fund other infrastructure and community amenity projects within existing borrowing limits.  
  • Through a special purpose vehicle (SPV), Crown Infrastructure Partners has raised the money which allows the facility to be built.  
  • Wellington City Council will collect the levy on behalf of the SPV, it does not set it.

Crown Infrastructure Partners:

  • The Sludge Minimisation Facility Levy Order allows a special purpose vehicle (SPV), called Sludge Finance LP, to charge a levy to most rate-paying properties in Wellington City Council’s rating area for 33 years, from 1 July 2024.  
  • This levy has enabled the SPV to raise $400 million from private financiers to reimburse Wellington City Council for the construction costs of a sludge minimisation facility in Wellington.  
  • The SPV is a wholly owned subsidiary of Crown Infrastructure Partners and are a Crown-owned company, listed under Schedule 4A of the Public Finance Act 1989.