Water  |  11h ago

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Work is about to start on the new Activated Sludge Reactor at the Christchurch Wastewater Treatment Plant.

Christchurch City Council has awarded the contract to HEB Construction. 

The Council is working closely with the contractor to get the site established as soon as possible, with construction expected to start early in the new year.

“This is such a major milestone for the project, I’m so thrilled we’re moving forward and can get work underway,” Mayor Phil Mauger said.  

 “We owe it to the local residents and everyone in Christchurch to construct an up-to-date new activated sludge system that's built for the future." 

This work follows the demolition of the fire-damaged trickling filters earlier this year, clearing the way for the new reactor.  

“Once the new facility is operational, it will provide a long-term solution to the odour issues experienced since the fire, while also reducing greenhouse gas emissions and increasing capacity to support our growing population,” Head of Three Waters Gavin Hutchison said.  

“We know the fire and its aftermath have had a significant impact on the community, and we appreciate how challenging this period has been. While it has taken time to get to this point, we can now move from planning into delivery, and that’s great news for the plant and the wider community.”  

Construction is expected to take about three years, with commissioning targeted for 2028.  

“It’s great to see this critical upgrade work progressing. It’s no small feat keeping the damaged plant running with minimal odour,” Mr Hutchison says. 

“Alongside this work, we’re about to start a project focused on repairing the clarifiers, which play a vital role in separating solids from treated wastewater before it flows to the oxidation ponds. 

“We’re currently trialling installing cutoff walls that will allow us to isolate the clarifier tanks. This is a key preparatory step for critical repair works scheduled to begin in March. 

Mr Hutchison says that if the trial is successful, the walls will be installed towards the end of this year, streamlining the upcoming repairs and reducing the impact on normal operations.   

“We look forward to working with the local community and keeping everyone informed throughout these important projects.” 

A community meeting is planned for December, where Council staff will be on hand to answer questions about the Activated Sludge Reactor project, the upcoming clarifier work, and ongoing operations at the treatment plant. This will be an opportunity for residents to learn more about the upgrades and share feedback. 

For more information and to sign up for updates, visit the project webpage.