Christchurch city councillors have approved a $7.7 million plan to add more aeration to the troubled Bromley wastewater treatment plant, a temporary measure aimed at reducing the persistent and noxious odors plaguing the city’s eastern suburbs. The vote, held Tuesday, comes after years of complaints from residents and a failed proposal by Mayor Phil Mauger to pump partially treated sewage into the ocean – a plan that drew swift criticism from fisheries officials and the regional council. The ongoing issue stems from a devastating fire in 2021 that severely damaged the plant’s infrastructure, leaving residents to endure what many describe as unbearable smells.
The decision to install 16 additional aerators is intended as a stop-gap solution even as the council awaits the completion of a major rebuild of the Bromley plant, currently slated for 2028. The aerators will increase oxygen levels in the sewage ponds, accelerating the breakdown of waste and, crucially, reducing the production of odor-causing compounds. Staff modeling suggests this will mitigate offensive smells on 95 percent of days, a figure that, while an improvement, fell short of what some councillors believed was necessary.
A History of Odor and Controversy
The problems at the Bromley plant predate the 2021 fire, but the blaze dramatically exacerbated the situation. The 19-day fire, which began on November 12, 2021, destroyed key infrastructure, leading to a surge in Biological Oxygen Demand (BOD) levels in the ponds – the primary cause of the offensive smells, according to council staff. An insurance settlement was finally reached to cover the repairs, but the lengthy rebuild timeline has left residents facing years of continued disruption.
This summer saw a particularly acute increase in complaints, with thousands reported each month and an abatement notice issued by the regional council. The pressure to find a solution intensified, leading Mayor Mauger to propose a controversial plan to discharge partially treated sewage into the sea. That proposal, however, quickly ran into opposition. Fisheries Minister Shane Jones publicly criticized the plan, calling it “absolutely unacceptable” and raising concerns about the potential environmental impact. The regional council also stated they were unaware of the plan, further fueling the backlash.
Debate Over Aeration Levels
While councillors ultimately approved the staff recommendation for 16 aerators, the debate highlighted a division over the scale of the response. Several councillors argued for the installation of 21 aerators, a more comprehensive solution modeled to reduce odor risk on 99 percent of days, at a cost of $11.2 million. Councillor Celeste Donovan voiced strong support for the larger investment, stating, “We need to do it once, we need to do it right.” She argued that the community had been “short-changed for too long” and deserved the highest level of protection.
Councillor Mark Peters echoed those sentiments, expressing frustration that the more robust option wasn’t prioritized. “I believe we don’t have any social licence out there in Bromley any longer,” he said, adding that the community had lost faith in the council’s ability to address the issue. Peters and Councillor Andrei Moore were the only two votes against the 95 percent reduction plan.
Councillor Yani Johanson also expressed support for the 99 percent option, stating, “We owe it to this community to minimise and mitigate the risk as much as People can.” He emphasized the need to prevent residents from enduring the “hell” they’ve experienced in the past.
Beyond Aeration: A Biochemical Additive
In addition to the aerators, the council is also exploring other potential solutions. A trial is underway involving a “biochemical additive product” designed to reduce odor. A council spokesperson indicated that details of the product would be released after the Easter break. The effectiveness of this additive will determine whether it is deployed more widely.
Residents of Bromley and surrounding areas have reported a range of health impacts linked to the odors, including migraines, nausea, respiratory issues, and mental health concerns. A community meeting last year highlighted the depth of frustration and the toll the ongoing issue has taken on residents’ quality of life.
What’s Next?
The installation of the 16 aerators is expected to take approximately three weeks, according to council staff. The council will continue to monitor the situation and assess the effectiveness of the aeration system, as well as the results of the biochemical additive trial. The long-term solution, however, remains the completion of the full plant rebuild in 2028. In the meantime, the council has committed to providing regular updates to the community on progress and any further mitigation efforts.
This is an ongoing situation, and residents are encouraged to continue reporting odor complaints to the Christchurch City Council. The council’s website provides information on how to submit complaints and access updates on the Bromley plant rebuild.
If you or someone you understand is experiencing mental health challenges related to the ongoing situation, resources are available. You can contact the Mental Health Foundation of Recent Zealand at 09 623 4810 or visit their website at https://www.mentalhealth.org.nz/.
Keep reading
