UK's rivers are clogged up with 'wet wipe islands', shopping trollies, lawnmowers and sex toys

Wet wipes that are wrongly flushed down household toilets are piling up on river shores, experts have said.

One mass on the edge of the River Thames has grown to the size of two tennis courts and is being labelled a "wet wipe island" by the Thames21 charity, which aims to improve the health of the London waterway.

Often used to remove make-up or for cleaning, the durability of wipes means they take a while to break down. As wipes are pumped along with sewage into rivers when sewage treatment works become overwhelmed, they get caught on branches, trapping sediment and forming masses that are unsightly and may pose a threat to river wildlife.

Campaigners exposing the state of Britain's waterways, say rivers are full of objects that have no place being there, including shopping trolleys, lawnmowers, sex toys and sanitary products. Some campaigners have even found a sofa and a piano keyboard during river cleans.

Wet wipes cause a further problem for rivers as they can release plastic fibres – found in 90 per cent of all wipes used in the UK – into the water. They also contribute to the phenomenon of fatbergs, which have been found in sewers.

Some wipes that meet certain standards are suitable for flushing away.

Debbie Leach, CEO of Thames21, said: "Wet wipes made with plastic fibres are contaminating our rivers and building up in large numbers on the River Thames foreshore, and the plastic is forming ‘wet wipe islands’ which are devastating for wildlife and for people… The situation is only getting worse."

Thames21 said wet wipes were by far the most common item recorded on the Thames foreshore, adding that they are physically changing its shape and sediment type.

In the past eight years, the charity has found "wet wipe islands" at six sites inside river bends in west London. It claims one in Hammersmith "has grown to the size of two tennis courts and over a metre tall in the past six years".

Following sewage overflows, wipes and other items such as sanitary products get caught on branches and twigs on the banks of the Thames, said Dave Morritt, Professor of Marine Biology at Royal Holloway, University of London.

"Because they’re designed not to fall apart, they trap sediment particles and then that sediment builds up and builds up and builds up and the consequences are that the whole profile of the shore changes because you get these wet wipes – I like to call them – reefs or islands.

"You can actually see these bits of land, if you like… if you’re walking along Hammersmith Bridge."

He said plastic fibres, regardless of their source, can be digested by fish and pass through their gut. The stomachs of some crabs are completely blocked with plastic.

The pollution of wet wipes from sewage, said Professor Morritt, "is a rather worrying insight into what people must be putting down the toilets – lots of these things aren't designed to be flushed down toilets".

The full impact of wet wipes and their microfibers on marine and river species is uncertain, according to Tom Allison, a PhD student investigating biodegradable wet wipes and their journey from wastewater to freshwater at Cardiff University.

"Ingestion of fibres commonly found in wet wipes has been observed in aquatic species, such as Asian Clams in the River Thames, which were close to wet wipes on the shore. It's challenging to trace these microfibres directly back to wet wipes, but due to the extensive pollution of wet wipes in rivers and on beaches, it's probable that many fish and other aquatic species are ingesting wet wipes.

"Wet wipes contain various chemicals, depending on their purpose, and sewage-derived wipes can quickly absorb pollutants during transportation. These attached chemicals and pollutants can enter aquatic species, causing harmful and toxic effects. In addition, intact wet wipes can cause physical blockages in the digestive systems of organisms which may be lethal. New research is now needed to confirm these interactions in the environment and to assess the extent of harm that these wet wipes may cause."

Professor Richard Thompson, director of the Marine Institute at the University of Plymouth, said wet wipes are also a problem in the wastewater treatment process because they can create blockages that may escape into the environment in overflows.

"The question, really, is what should we be putting down the toilet in the first place rather than expecting a wastewater treatment plant to magically remove anything that we choose to flush.

"We need wastewater treatment plants that can handle pee, poo and paper but beyond that, it starts to get a little bit more challenging."

In addition to the unwanted items that pass through the sewage system and into rivers, Britain's waterways are suffering because they are being used as a dumping ground by some people.

Steve Frost, environment manager at the Angling Trust, said there were so many shopping trollies found in Manchester's River Irwell that "they were acting as gabions, holding back flow and raising the riverbed level, [which is] not good for flood control".

Mr Frost said plastic bottles and cans were the most common find in rivers, according to reports from anglers.

They have also found the grill of a car, detritus from a cannabis farm, sanitary products dangling from trees, used syringes, road signs, traffic cones, a piano keyboard and a settee.

Mr Frost said: "My reaction is one of sadness that so many people think that our rivers are just somewhere to dispose of unwanted rubbish.

"Last week I saw a lawn mower in a small stream in Norfolk. Why?

"When I see a river, I just marvel at the mystery of what is inhabiting the water. All rivers have a dynamic beauty as they tumble, spill or meander through our landscapes and towns. I do not understand the mindset that allows people to use them to dump rubbish."

He added: "I can claim a [sex toys] from my local river, not something I boast about."

Mr Frost is not the only person to find a sex toy.

"When I was at [local member Trust] Thames21, we found an unexploded Second World War bomb, a handgun, several safes and a child approached me on one memorable clean-up with a very large, rubber sex toy asking me what it was," said Mark Lloyd, chief executive of the Rivers Trust.

"I told her to ask her mother and fled to the other end of the event. One interesting feature was that similar items of rubbish tended to concentrate on particular beaches. There was one where there were lots of shoes, one for umbrellas, and another for polystyrene. I think it was to do with their particular hydrodynamic properties. Probably the most common item used to be plastic cotton bud sticks, which everyone thought were lollypop sticks. They align with the flow in sewage treatment processes and are hard to screen out."

Joy Godfrey, who campaigns for a cleaner River Esk in Scotland, said she had found "entangled strands of wet wipes covered in dark stinking sludge, multitudes of fresh white sanitary towels washed up over rocks, tampons scudding along the riverbed and extensive clusters of disintegrated toilet tissue along the quieter edges of the river".

"When children swim in that toilet paper, they are swimming in people's poo," she said.

"Everything we flush could end up in the river. Everything we pour down the sink could end up in the river."

River cleans organised by British Canoeing in 2022 – involving 1,228 volunteers from 103 English canoe clubs and 2,456 hours of cleaning – resulted in 704 sacks filled with 2,123 single use plastic bottles, 1,476 cans, 831 glass bottles and 3,296 food wrappers.

The most unusual finds included a footstool, a computer monitor, an electric scooter, a doll's leg, a water pistol, a highchair and dental floss.

Campaigners with the South East Rivers Trust once found a postbag full of leaflets that "had melted into a sort of slime in the river in Tonbridge".

In the same river, they found seven metal trollies in a stretch of two miles.

And the Rochester Esplanade yielded a small fridge.

Gloria Francalanci, plastics project manager for the South East Rivers Trust, who organises cleanups along the River Medway, said: "When we find strange items we are always left with a mix of surprise and frustration because many of them still have value – or would have done before they ended up in the river.

"In Maidstone, once we found a complete outfit – jeans and a jacket. Why throw them in the river and spoil the environment when you can take them to the charity shop or a clothes bank? We have so many opportunities to recycle now."

i and its sister title, New Scientist, have launched a joint campaign, Save Britain's Rivers, to rescue the country's polluted waters.

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