Drone footage shows significant damage at wastewater plant after blaze

Friday, 5 November 2021

Christchurch City Council has released drone footage of the fire damage to two filter buildings at the Bromley wastewater treatment plant.

Drone footage has revealed the significant damage caused by a large fire that broke out at Christchurch's wastewater treatment plant earlier this week.

The roofs of two buildings housing filters collapsed during the blaze, which sent a plume of thick black smoke up into the air, leading to a public health warning.

The roofs were made of plastic, reinforced with fibreglass.

Christchurch City Council, which owns the plant and supplied the drone footage, is now planning to install a sprinkler system over the damaged buildings, which it says will help reduce a lingering smell being produced by the damaged filters, still smouldering more than four days after the fire broke out.

* Extent of damage unclear as council assesses fire-ravaged wastewater treatment plant

* Council not yet able to assess damage after wastewater treatment plant blaze

Drone footage of the fire damage at Christchurch's Bromley wastewater treatment plant. Two trickling filters were damaged by the fire.

* Investigation into fire that tore through wastewater treatment plant

“In the interim, we are pumping clear wastewater over the filters to prevent re-ignition of the fire. We hope to be in a position to be able to stop doing that by early next week,” said council water boss Helen Beaumont.

Christchurch City Council hopes to put sprinklers across the top of the two filters to help address the smell it is creating.

“It is also possible that there is some organic material within the plastic media which is decomposing.

“We have put in place misters to suppress the odour and will be investigating de-odourising chemicals over the next few days.’’

The council has also been forced to make changes to its wastewater treatment process, which is potentially adding to the odour issues, and is working with Environment Canterbury to minimise any adverse effects discharges from the plant may have on the air or ocean.

Firefighters tackling the blaze from the air on Monday. It began about 3pm.

On Thursday Beaumont said the council was “assessing options” for getting inside the buildings.

Hot spots remain deep inside the filters within the buildings, which are now covered by the burnt and melted roof debris.

Only visual inspections of the damage have taken place so far. Beaumont said these had confirmed there was no immediate risk of the filter buildings collapsing.

A complete inspection can only happen once hot spots have been dampened down and most, if not all, of the “material” inside the filters have been removed.

“This is going to a challenging logistical exercise,” Beaumont said.

The two damaged filters are now being bypassed in the wastewater treatment process – and the true effect on the cleanliness of treated wastewater being pumped into the ocean may not be known for over a fortnight.

Beaumont has not speculated on the cost of replacing the filters, or how long it may take.

Despite the damage, the wider wastewater plant in Bromley is still running. Residents do not need to change any habits, such as flushing toilets.

The council has employed an independent investigator to work with WorkSafe and Fire and Emergency NZ.

The cause of the fire remains unknown.

Contractors were refurbishing the roof of one of the filter buildings, and had been doing so for a number of weeks when the fire broke out.