Holiday close-down
20 December 2024
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
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.
Increase in odour during summer transition
6 December 2024
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, and results 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 16th 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.
Demolition of trickling filters underway
Demolition of the Christchurch Wastewater Treatment Plant’s fire-damaged trickling filters has started and quick progress is being made to bring the walls down.
We’re aiming to have the walls of the trickling filters down by Christmas and in the new year we’ll shift our focus to removing the foundations.
Insurance settlement secures future for treatment plant
9 October 2024
An activated sludge reactor will replace the fire-damaged trickling filters at the Christchurch Wastewater Treatment Plant to fix long-standing odour issues impacting local residents.
Christchurch City Council and its insurer have settled an $85 million insurance claim following the fire in 2021, which destroyed two trickling filters at the plant in Bromley.
The filters were a critical part of the sewage treatment process, and the damage impacted the treatment process causing major odour issues that have affected the local community.
The settlement was approved by Councillors unanimously and follows complex negotiations. Confidentiality was required for these negotiations so we could get the best outcome for residents and the environment.
FENZ fire investigation report published
16 December 2022.
We have just received from FENZ their Fire Investigation Report – Shuttle Drive, Bromley, Christchurch City [PDF, 5.1 MB].
Consequently, we have not had an opportunity to consider it fully. Our own investigation is ongoing and we will not be commenting further.
Snapshot of hydrogen sulphide levels decrease
2 November 2022.
This graph shows how the hydrogen sulphide levels coming from the oxidation ponds has significantly decreased over the four months from 10 June to 10 October 2022.
The activated sludge plant was made operational on 28 July, with the biology reaching full maturity on 17 August, despite the challenges of growing the biology over the middle of winter.
It took four weeks for the better-quality wastewater to flush through our network of six ponds, with the odour substantially reduced by mid-September. This was in line with the timeframes that we promised the community we'd work to.
Hold off from cleaning your house
30 September 2022.
With hydrogen sulphide levels dropping and the days warming up, it might be tempting to clean any discolouration off your house that might have been caused by a chemical reaction between lead paint and hydrogen sulphide.
We ask that you keep waiting. Before we begin encouraging people to clean their homes, we'd like to see at least four weeks of low hydrogen sulphide levels and improved weather to get an idea of how any discolouration fades.
We're about to start monitoring some 'test houses' and will provide updates on our website to show how the discolouration improves.
If you absolutely must clean your house now, make sure you're familiar with our list of dos and don'ts that we published last month.
Do:
- Read the report findings and information(external link) on house discolouration.
- Wash your walls with a commercial chlorine-based solution, or warm, soapy water. This could help remove any organic dust, common moulds and some discolouration. The presence of these common moulds is not linked to the wastewater treatment plant fire.
- Adhere to the manufacturers’ proprietary ratio recommendations if you use a commercial chlorine-based solution.
- Several washes might be required.
Don't:
- Don't use a high-pressure washer to try and clean any staining or discolouration, as this could result in flakes of lead-based paint entering the environment.
- Don't exceed the manufacturer’s proprietary ratio recommendations if you use a commercial chlorine-based solution.
Our team is keeping a register of homes that have reported paint discolouration. If your home has discolouration and you haven't let us know, or if you'd like more advice about what to do, email wastewater@ccc.govt.nz.