Fatbergs clogging New Zealand pipes caused by fats, wet wipes

Long Lunch 26/07/2018
Photo: Getty.

New Zealanders are reminded that their actions have a direct effect on wastewater pipes and potential overflows.

New Zealand sewerage systems are plagued with ‘fatberg’ build-up that clog up the pipes, which cost $1 million a year to remove.

A fatberg is precisely what it sounds like – a large, congealed mass of fat found in wastewater pipes. The hardened lumps are caused by hot fats or oils poured down the drain that then solidify in the sewerage system.  

“People are under the impression that because the fat flows, it’s going to be fine. But once the hot liquid hits the cold pipes they sit and form these hard lumps called fatbergs,” said Roseline Klein, head of water at Watercare Services.

Nappies and wet wipes have also been found to cause fatbergs because of their inability to break down easily.

According to a BBC report, wet wipes were behind 93 per cent of blockages in UK sewers.

Ms Klein told RadioLIVE that about 4 percent of Auckland’s sewers combine both stormwater and wastewater, which can overflow after heavy rain.

Watercare contractors revealed that fatbergs were responsible for a recent overflow of waste and toilet paper onto south Auckland properties after a heavy rain.

But completely blocked pipes could exacerbate overflow, rain or shine regardless.  

A sinkhole opened up in Dannevirke in February 2017, after a mass of fat (and rats, who had been feeding on it) caused a sewer pipe to fail.

In September 2017, Waikato councils launched a campaign to educate people on pipe blockages after a 250-metre long, 130-tonne fatberg was discovered in a London pipe.

What can you do to help?

Watercare advises New Zealanders to allow fats and oils to cool before disposing them in the rubbish bin. It’s also recommended to avoid flushing nappies and wet wipes down the toilet. 

Listen to the full interview with Roseline Klein above.

The Long Lunch with Wendyl Nissen, 12pm - 3pm on RadioLIVE and streaming live to the rova app on Android and iPhone.