The disgusting, slimy junk clogging up sewer systems

So-called 'flushable' wet wipes are among the disgusting items clogging up sewer systems.

The horrific sight of a mound of oily, stinking wipes - among other junk - was shared by the Charleston Water System, in South Carolina, on Twitter earlier this week.

Divers adventured more than 30 metres into a raw sewage pipe to find out what was blocking it.

They came up with a massive, black, slimy, filthy mound of wet wipes and baby wipes that had been flushed down the toilet.

While some companies market such wipes as "flushable", the Charleston Water System stressed that's not the case.

"You should only flush #1, #2, and toilet paper," a representative wrote on Twitter.

Another image contained a baseball and a large piece of twisted metal, alongside "many other non-flushables".

"We made this pic low-res for your benefit," the picture was captioned.

Wet wipes are woven together and don't break down in water, clogging up sewage pipes. They can then collect grease and other junk floating through the sewage, congealing into a disgusting and unmovable mound.

It's also been an issue in New Zealand, with Watercare calling it a "constant battle".

"We've not found one [wet wipe] that breaks down like common toilet paper. I mean, physically, yes you can flush them down the toilet, but it causes big problems," Peter Rogers, Watercare's manager for asset protection, told Newshub last year.

Earlier this year, Associate Minister for the Environment Eugenie Sage floated a potential ban and said she was keeping a "close watch" on what was happening overseas.

"Consumers can think about the impacts of convenience products like wet wipes," she told Newshub at the time.

"At the very least they need to go in the bin after use, not down the toilet. Re-useable cloth flannels are a better option."

To get clean after their filthy adventure, the American divers were given a bleach bath - still in their wetsuits.