“Fatbergs” accumulate when foreign objects flushed down toilets bind together, and during the months the state was locked down there was a noticeable spike in drain blockages.

“Things like wet wipes, nappies, sanitary products, toys, money, even a bedsheet, people’s mobile phones, sometimes the odd engagement ring – you know, all those things [that] shouldn’t be going down the toilet,” the Water Corporation’s Clare Lugar said.

The grubby matter – mixed with oils, grease and fats that wash down the sink – result in fatty lumps of hard and pungent crud that blocks pipes and triggers sewage spills.

“Fatbergs really are a problem for us because they clog up our pumps,” Ms Lugar said.

“If those pumps can’t run it means that wastewater starts to back up in the system – and nobody wants that because it can overflow.”

Ms Lugar said the Water Corporation has had to use cranes to dislodge mammoth fatbergs and cart them to landfill.

“The other word that we use for a fatberg is actually a pipe monster and it is a monster,” she said.

“I’ve seen some in other wastewater systems around the world as big as a bus.

Ms Lugar kindly described the smell of fatbergs as “distinguishable”.

“It can linger in your nostrils for some days. It is not pleasant, she said.”

Unflushables spike coincides with surge in toilet paper panic-buying

While the Christmas holiday period was typically the busiest time for drain clean-up crews, the Water Corporation noted spikes in blockages between February and May while WA was in lockdown.

The working theory is people working from home – and potentially the panic-buying of sanitary products – could have contributed to the spikes.

“We certainly noticed that during that period … we did see that spike in blockages caused by things like wet wipes, sanitary products and things like that being flushed down the loo,” Ms Lugar said.

“When at work people may have put those items in a special bin – usually in the workplace [there are] bins to put those things in there and they’re taken away and disposed of.

“I think with people being at home they may have been unsure what to do and probably put more of those things down the loo.”

By the end of the year, the Water Corporation had responded to almost 3000 wastewater blockages across its network.

That was slightly higher than the previous two years.

The number of blockages caused by non-flushable products during February to May 2020 was almost double the number in the same period in 2018.

The Water Corporation responding by ramping up a process called “de-ragging”, manually clearing non-flushable items from wastewater pumping stations and in the process dragging out stinky fatbergs.

The port city of Fremantle was the worst suburb in Perth for blockages caused by rags such as wet wipes, easily beating Nedlands, Cottesloe and Armadale, which also rounded out the top 10.

Victoria Park, Mosman Park, Armadale and Mount Lawley were the top four suburbs where blockages were caused by fats, oils and grease.

‘Think before you sink’

Ms Lugar urged people to ‘think before you sink’ and use their bins rather than scraping oils, fats and food scraps down the sink.

Here are some simple tips to remember that can save the sewer system:

• Transfer cooking fats and oils into a sealable container. Once cooled and solidified, place the container into the rubbish bin
• Place a bin in your bathroom to avoid people flushing nappies, sanitary items and other materials down the toilet.

Do not:

• Pour boiling hot water down the sink to try and dissolve cooking fat. Doing so will only melt the oil, which will eventually cool down and solidify in the pipes
• Flush wet wipes, tissues, paper towels, cotton wool buds, sanitary products or nappies. Please dispose of these products in the rubbish bin.

What about ‘flushable’ wipes?

Wet toilet wipes may say “flushable” on the label, but Ms Lugar said that was misleading.

“Even if it says flushable on them, they’re probably not going to break down in the wastewater system, and they are going to cause a huge problem for us,” she said.

“Pop them in the bin instead of flushing them.”

She said water authorities across the country were lobbying manufacturers to change the labelling.

“Only paper, pee and poo down the loo – anything else needs to go into a bin.”

–ABC