Christchurch City Council says it is still business as usual for its main wastewater treatment plant - despite fire tearing through the site.
The fire at the Christchurch wastewater treatment plant. Photo: RNZ / Nate McKinnon
But the Council Three Waters and Waste head Helen Beaumont said the treated water that flowed out to sea would not be up to the usual standard.
Backup systems using additional chemical processes were being used to produce the best result possible, she said.
"We've had extensive damage to our trickling filters and they are now offline. We won't be able to use them. However, the fire is out we understand. The water was turned off about 11am this morning and there was no smoke coming off those filters and the firefighters were on standby to look out for hotspots," Beaumont told Midday Report.
"The wastewater treatment has many treatment process stages so luckily for us we can bypass those trickling filters and keep that treatment plant open and deal all incoming sewage more or less business as usual.
"We will optimise those processes we've got in terms of the primary settling tanks and clarifiers and also the oxidation ponds which are still there and we can use those before the sewage goes out through the long ocean outfall.
"We're fairly confident that we can ... still do a pretty good job on treating that sewage."
An independent investigator was working with Fire and Emergency NZ and WorkSafe to determine the cause of the blaze, Beaumont said.
"We will work with them to sort out what happens next."
The fire began yesterday and up to 50 firefighters were tackling the blaze at the Bromley plant at its peak