Increase in odour during summer transition

There has been an increase in odour coming from the Christchurch Wastewater Treatment Plant as the plant transitions to summer mode.

When the weather is warm and dry, the wastewater entering the plant is more concentrated. This puts more pressure on our temporary systems, which have been struggling to deal with the increase, resulting in more odour.

We have plans in place to deal with seasonal changes but it’s not possible to predict all the variables that impact plant operations and odour.

Our staff are aware of the increase in odour and have made changes to our operations to stabilise the treatment process and reduce odour.  We’ve increased the number of aeration lanes in service from one to three, which increases our treatment capacity. We’ll keep a close eye on this to ensure we can control the amount of activated sludge growing in the aeration basins, and will continue to tweak operations as needed.

Of the 16 aerators on the ponds, 15 are operational, and we’re working on getting the 16^th working again as quickly as possible.

We anticipate that the treatment process will stabilise in the next few days and odour will progressively reduce over the next week or so.

We’re doing our best to keep the plant running in its damaged state and appreciate your patience as we deal with this increase in odour.

Latest hydrogen sulphide monitor results

As explained above, there has been an increase in odour as the treatment process adjusts to summer mode. We’re making changes to our operations to address this and anticipate the treatment process will stabilise.

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  

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.