Demolition of trickling filter foundations underway 

Work has now started on the demolition of the trickling filter foundations. The photo shows activity at the site on Tuesday 17 December. 

Our team is busy preparing for the holiday break. This includes tidying up the site to ensure everything is safe and sound, and so we can hit the ground running in the new year. Once work starts back on 6 January our contractors will be focused on removing the centre column and foundations. 

Holiday close-down

Demolition work

Our contractors will stop work for the holiday period on Friday 20 December. Demolition will resume on Monday 6 January.

Operations 

Our dedicated operations team will continue working throughout the holiday period to keep the plant running as efficiently as possible. Our team will continue to monitor and make changes to our processes as needed to minimise odour. 

Keeping the plant running in its damaged state is challenging and there will always be an element of unpredictability, but our team is experienced and quick to respond to whatever is thrown at them.

Communications

This will be our last communication about the Christchurch Wastewater Treatment Plant for 2024. We'll be back on board from 6 January and our communications via website, e-newsletter and social media will resume then. 

Even though you won't hear from us again until next year you can rest assured that our team is working hard to keep the plant running and will do all they can to address issues if they arise. 

Hydrogen sulphide results

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.

Staff have been taking action to address odours including:

• reducing the number of primary tanks in service to prepare them for the lower flow experienced over summer.
• increasing the number of aeration lanes on the temporary activated sludge plant to prepare it for the lower, but more concentrated sewage flows over summer.
• changing the flow-path through the oxidation ponds to prepare them for summer.

These changes seem to be working and the amount of odour detected at community monitoring sites has reduced.

When there’s an increase in odour we take action straight away but it can take a bit of time for this to have an impact on odour. This is due to how long it takes for sewage to pass through the treatment plant and ponds. As a result, it takes time for any operational changes to effect and reduce the odour being released.

Staff will continue to monitor and make changes to the processes as needed to minimise the odours being released.

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.