Christchurch Wastewater Treatment Plant update

19 April 2024

Oxidation ponds - transition to winter mode complete

As we move into winter, and temperatures cool down, the biology of the ponds changes. In previous years this has resulted in a short-term increase in odour coming from the ponds. This year our team is trialling a new way of operating the ponds during this period to reduce odour.

During this period wastewater is being diverted past the ponds located close to residential properties. Skipping these ponds entirely will reduce the impact on neighbouring residents and wastewater will also spend less time in the ponds overall. We'll be monitoring the ponds closely to see if these changes are effective in reducing odour while ensuring we don’t exceed our ocean discharge limits. 

All 16 aerators are once again in service following repairs to a vertical shaft aerator and disc aerator. 

Community board presentation available online

On Monday 8 April Council staff gave the Waitai Coastal-Burwood-Linwood Community Board an update on work underway at the treatment plant. A recording of the meeting is available online. Skip forward to 24:43 to see the presentation on the Wastewater Treatment Plant. 

Hydrogen sulphide monitor results

We are continuing to detect H2S in residential areas when the wind blows in that direction from the plant. Levels detected tend to be highest when the wind speeds are low and do not disperse the odours as readily.

Where to get help

If you need health support, we have information available on our website. This includes information on Pegasus Health's Partnership Community Workers and contact numbers for Healthline and counselling services.

Stay updated

We want everyone to be able to stay updated on our response and recovery from the treatment plant fire, and we regularly post new information and reports 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.