Christchurch Wastewater Treatment Plant update

Tuesday 10 February 

The latest

Our team carried out its usual assessment of the ponds today, supported by drone imagery taken on site. The overall condition of the pond system remains similar to yesterday. We are still seeing lower-than-ideal dissolved oxygen levels in places, especially in the early morning. This means there is an ongoing risk of odour.

However, the warmer, sunnier conditions are helping to support our algae activity across the pond system and we are seeing some really encouraging dissolved oxygen levels during the day. 

New aerator installed in Pond 2B

A new aerator was successfully installed in Pond 2B this morning and is now operating (shown above). This additional aeration will support the pond’s recovery and help reduce the likelihood of odour as the system stabilises.

As with any new aerator, there was the possibility of short‑term disturbance of the sludge layer as it started up. This was not detected during monitoring and we believe that the risk of an increase in odour related to this has now passed. 

Neighbourhood visits 

Around 32 Council staff have been out today visiting roughly 750 neighbouring households to hear directly from residents about their priorities.

If no one was home, staff will have left contact details so people can still get in touch. The information collected will help inform possible options for community support, noting that any decisions would need to be made by the elected Council.

Tree removal 

From tomorrow (Wednesday) through to Saturday, an arborist will be on site to remove up to 12 non‑native trees located near the contractor village. These trees have been dropping branches recently, and an inspection confirmed significant internal rot.

We need to remove the trees now as construction activity is ramping up and there is an increased number of contractors moving through this part of the site. Because the trees are unstable and have been shedding large branches, they pose a real safety risk to people working in the area.

Each tree removed will be replaced with two new trees. These replacements will be included in the overall landscaping design for the area surrounding the new activated sludge plant.

No change to odour status map 

With conditions largely the same as yesterday there have been no changes to the odour status map. 

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.