Combination of factors causing fatbergs in Western Bay

Wastewater pipe blockages can be caused by congealed grease and fat binding with things that shouldn't be flushed.

People are being urged to “pause before you pour” after an unusually high number of fat, oil and grease blockages in Western Bay’s wastewater pipes.

Over the past three months, there have been six instances in the district where wastewater has overflowed into the stormwater system because of pipe blockages.

This compares to seven overflows for the entire previous financial year, in which clean-up costs totalled $47,000.

Western Bay of Plenty District’s general manager, infrastructure group, Cedric Crow, says wastewater pipes can block for several reasons, including wet wipes and other items being flushed down the toilet.

Congealed grease and fat from kitchen wastewater bind to this debris in the pipes creating masses commonly referred to as “fatbergs”, he says.

These “fatbergs” cause wastewater to back up, until it spills out onto the street, ending up in stormwater drains which then flow into rivers and the sea.

In cold weather fats solidify faster, which could explain the spike in blockages, says Cedric.

Blockages can cause overflows like this one.

“Another contributing factor could be people using cheaper cuts of meat because of rising food costs,” he adds.

To dispose of fats and oils, they should be poured into a container and thrown out with the rubbish once they have set.

“Use containers that would go in the rubbish bin anyway, like the small yoghurt punnets which are number six plastic and can’t be recycled.”

Cedric says people should also avoid flushing wet wipes, even those that say they are “flushable”.

“Toilet paper is made from wood fibre and breaks down easily when it’s flushed, but wipes tend to be made using petrochemicals that take longer to break down.

“It’s not a very pleasant topic to talk about, but it’s even more unpleasant when there’s an overflow. We’re asking people to be mindful of what goes into the wastewater system, so we can avoid unnecessary clean-up costs and negative environmental impacts.”