Christchurch Wastewater Treatment Plant update

Friday 20 March

Current pond health

Since our last update on Tuesday, we’ve continued to see slow and steady improvement in pond conditions. This progress is reflected in our pond health tracker, with two ponds recently upgraded in status.

On Wednesday, site staff detected an intermittent odour coming from the treatment plant itself. A thorough investigation was undertaken by staff, however, we were unable to identify the source at the time. As the odour has since subsided, pinpointing the cause remains challenging. We will continue to monitor and investigate should it reoccur.

What to expect this weekend

While we’re encouraged by the ongoing improvements, the settled weather forecast for the weekend may allow for occasional odours from the ponds. These are expected to be intermittent and not strong or long-lasting.

As we transition into the cooler months, it is normal to see some fluctuations in oxygen levels and pond biology. These natural changes can occasionally result in short-term increases in odour, particularly overnight or during calm, still conditions.

The latest from Gary 

The overall programme is expected to span about three years, with commissioning targeted for 2028.

I’m also making myself more available in the community. I’ll be at the Bromley Community Centre every Monday and Thursday between 10.30am and 2pm. Please feel free to drop in if you’d like an update, want to chat about what’s happening on site, or just want to say hello.

I’m also working on securing some times at a venue closer to Shortland Street and hope to have those confirmed next week.

If you'd prefer to get in touch directly, you can always reach me by email at gary.watson@ccc.govt.nz. 

I’ve also contacted health officials to request an updated health advisory, and I’m hoping to have more information to share with you next week.

The long-term fix: activated sludge reactor construction update 

Work on this phase of sheet pile installation is nearly finished, and we expect to wrap this up by the end of the week. Once completed, our contractor will move on to excavating the final section needed for ground improvements. We expect this work will be finished by late March or early April.

The team installing the stone column piles has now arrived on site with their crane and drill rig. They are ready to begin installing the trial column this coming Monday.

All vibration and noise-monitoring equipment is set up and providing real‑time information.

Stay updated

We want everyone to be able to stay updated on what's happening at the Christchurch Wastewater Treatment Plant, and we regularly post new information on ccc.govt.nz/wastewaterfire 

You're welcome to send this update to your networks. If you know someone in the community who doesn’t have email or internet access, please print this newsletter off and pass it to them.

If you know of anyone who would like to receive this e-newsletter they can subscribe online. 

If you have any questions, or would like further information on the project, please call us on 03 941 8999 or 0800 800 169 or email wastewater@ccc.govt.nz  

Thanks for your patience and understanding. We’ll be in touch again soon.