Fat berg: Wet wipes and fat blocking Palmerston North wastewater pipes

Wet wipes are clogging the wastewater system in Palmerston North.

Palmerston North residents are being urged not to flush wet wipes after “fat bergs” have caused blocks to the wastewater network.

Wet wipes and other non-flushable materials have caused significant disruptions in recent weeks, leading to blockages to pump stations and pipes in Highbury and Awapuni suburbs.

The wipes mix with fat and grease to create “fat bergs”, a nightmare collection of wet wipes mixed with congealed fat.

Council three waters group manager Mike Monaghan says only the three Ps should ever be flushed down the toilet: pee, poo, and toilet paper.

“Paper towels and tissues are highly absorbent and 90% of wet wipes on the market are also produced from nonwoven fabrics made of polyester or polypropylene,” he said.

Wet wipes are clogging the wastewater pipes in Palmerston North.

“These products don’t break down well in pipes. They cause blockages when they mix with fats, oils, and grease that go down household sinks,” he said.

Every year, up to 12.9 billion litres of wastewater is collected from 31,700 homes or businesses around Palmerston North. Pumps move wastewater along a 405km network of pipes - the distance between Palmerston North to Hamilton if they were laid end-on-end.

Blockages in wastewater pipes cause the water to back up, increasing pressure. This can cause manhole covers to lift and wastewater to escape.

“Blockages not only disrupt the public wastewater system but if you flush them down your home or business toilets, they could also impact your own property’s internal plumbing leading to costly repairs,” he said.

The issue wasn’t Palmerston North’s alone. Councils around New Zealand urge their residents not to flush wet wipes down toilets and have similar issues.