Source: Radio New Zealand
Bromley Wastewater Treatment Plant.
The Christchurch City Council is investigating pumping millions of litres of screened and chlorinated sewage into the ocean each day in an effort to mitigate the putrid stench coming from Bromley’s damaged sewage treatment plant.
The council was last week hit with an abatement notice after Canterbury Regional Council received more than 4500 complaints about the odour in the past month.
The plant was damaged by fire in 2021 and the smell of sewage has wafted over the eastern parts of the city since then, but has been noticed in the central city and been markedly worse this year.
The council said about 25-30 percent of the city’s sewage would be partially treated and mixed with chlorine before bypassing the treatment ponds and being diverted directly to the ocean.
The council did not confirm the volume of sewage destined for the ocean under the plan, but its own website stated 185 million litres flow through the Bromley plant every day.
The council blamed cooler temperatures and high rainfall for reducing oxygen and algae in the ponds and causing the current offensive odour.
Christchurch mayor Phil Mauger said the council had to act and had been in discussions with Canterbury Regional Council and mana whenua.
“Because the wastewater treatment plant has been running on a knife edge since the fire, the ponds have been overloaded and are now in poor health,” Mauger said in a statement.
“We can’t sit back and expect conditions to improve on their own.
“Anyone who lives nearby knows the odour issues have become more intense and we’ve been looking at all ways to help alleviate the stench. Reducing the amount of wastewater entering the ponds will take the load off, give them space to recover and – most importantly – address the current odour. If we can reduce how much wastewater is going into them, it will help stabilise pond conditions while the longer-term rebuild of our new treatment plant continues.”
Mauger was not immediately available for an interview and the council’s statement did not say when the plan would come into effect, how much sewage would be pumped directly into the ocean or for how long.
“There are a number of elements to work through to get this up and running. Staff are developing a plan as quickly as possible and will keep residents updated as this plan progresses,” the council said.
“The council would continue to look at further actions to improve pond health and reduce odour,” Mauger said.
The council could not say how the sewage would be treated, how much the plan would cost, nor how long it would be in effect.
When asked if the regional council had been consulted about the proposal and whether it would comply with consent conditions for the plant, the council responded: “We are in discussion with Environment Canterbury. Yes, we would meet consent conditions.”
However, Canterbury Regional Council director operations Brett Aldridge said it had not been formally consulted about the proposal.
“We are very surprised and concerned this has been announced without those detailed discussions,” Aldridge said.
“Environment Canterbury (Canterbury Regional Council) is meeting with CCC on Wednesday, when we expect to hear about their proposed plan to stop the stench in Christchurch. Environment Canterbury also expects the city council to include and consider mana whenua in their communications.”
It was not possible to speculate if any special permissions would be needed due to a lack of detail, Aldridge said.
“The current consent requires the wastewater to be treated.”
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– Published by EveningReport.nz and AsiaPacificReport.nz, see: MIL OSI in partnership with Radio New Zealand
