Christchurch Wastewater Treatment Plant update

27 May 2024

Odours increase as pond biology changes 

For the past two months we have been closely monitoring the oxidation ponds, looking for signs the ponds were changing from summer to winter mode. During this time, we were operating the ponds in a different way to try and minimise odours over this period. The biology of the oxidation ponds changed over the past couple of days due to the drop in temperature as we move into winter. As expected, this has caused an increase in odour coming from the ponds.

All the treatment processes at the wastewater treatment plant are working as well as can be expected, and the temporary activated sludge treatment plant process is also operating well. Based on our knowledge and experience from last year we expect that the increase in odour will last for a couple of weeks at most. The weather forecast for the coming week is cold, settled, and dry, which may make the odours worse in the short-term.

We know that any increase in smell causes stress for the community and we’re doing everything we can to reduce the duration and severity of odours. Keeping the damaged plant running is an ongoing challenge but our team is doing their best to respond quickly as conditions change.

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.