When Russell Brand and Bear Grylls took a dip at Henley-on-Thames in late April for Brand’s much-vaunted baptism, let’s hope for their sake that the water was first tested for E.coli. British waterways are rife with the harmful bacteria, along with other nasties, and for the thousands of keen outdoor swimmers diving into the waters this summer, the levels of pollution and sewage is cause for alarm.
In response to the rise in recreational use of water, the Royal Academy of Engineering published a new report, outlining the need to step up the protection of the quality of water in the UK’s rivers. Backed by Chris Whitty, it covers the quality of water in the UK’s rivers – and how human faecal matter is being discharged from sewage treatment works into waterways, rivers, wetlands and estuaries.
“Our [water] infrastructure is ageing and likely to be put under increasing stress from urbanisation from population growth, and it’s being increasingly impacted by the severity and frequency of storms linked to climate change,” says David Butler, a professor of water engineering at the University of Exeter who worked on the report.
Britain’s water systems were never designed to completely kill off all the bugs in wastewater by the time it flows into our rivers, notes Barbara Evans, a professor of public health engineering at the University of Leeds. Instead, the idea was that it would become diluted in waterways.
“But the population has grown a lot in the 170 years since our amazing system was built and the climate is changing,” she says. “So one of the things that is happening is that there is more waste water being produced now.”
Yet the rise in popularity of outdoor swimming continues unabated, with an astonishing 7.5 million people swimming in the UK’s open water and in outdoor pools in 2019 – with numbers rising. “There’s something lovely about river swimming,” says Tessa Wardley, from The Rivers Trust, who is a marine and freshwater ecologist and author of Mindfulness in Wild Swimming.
“Being in flowing water gives you a whole different feeling,” she continues. “And because you’re swimming at a lower level than the surrounding land, you see wildlife – kingfishers, birds and fish – up close and in a whole different way.”
Year-round outdoor swimmer and STA open water coach Ella Foote, author of How to Wild Swim adds: “Swimming along a river is a wonderful way to explore an area. Many of our rivers have public footpaths and green space for recreation. Unlike lakes and ponds, which are often on private land, they are free to use.”
The popularity of wild swimming soared during the Covid pandemic as an antidote to lockdown loneliness and has health benefits ranging from improved circulation to natural pain relief, as well as improving fitness and toning. But the benefits go beyond the physical. A study by the University of Bath found that swimming in nature was shown to improve wellbeing and positive mood, while also reducing tension, anger, fatigue and symptoms of depression and anxiety.
So knowing what’s actually lurking in that water has never been more important, because many of our rivers are, at times, choked with sewage as well as urban, agricultural and industrial pollution. Due to the unprecedented amount of rainfall during the past few months, the E. coli levels are particularly high.
Legal targets to improve the state of England’s rivers, lakes and coastal waters will be missed by a “considerable margin” without more action and funding, the Office for Environmental Protection (OEP) has warned. The environmental watchdog has found both the Government, and the Environment Agency (EA), are off track to meet targets for 77 per cent of England’s water bodies to reach good condition by 2027.
And while news that the Government has designated 27 new bathing sites in England is welcome, the designation doesn’t mean these sites, which include a dozen river beauty spots including the River Dart in Devon and the River Ribble in Lancashire, are guaranteed to be clean enough for swimming.
In fact, it simply means that there will be a testing regimen undertaken at these sites from May to September, with samples taken to test for E. coli and intestinal enterococci, both of which indicate the presence of sewage in waterways.
The health risks of swimming in UK rivers
“The most dangerous pathogen found in our rivers is E. coli which, if ingested, can cause chronic diarrhoea and vomiting and can, in rare cases, kill you. If you have an injury, you could get sepsis from it,” says Charles Watson, the founder of River Action UK.
“With the high levels of rainfall, huge quantities of raw sewage have been pouring out from our water companies directly into rivers. The combined sewage system in the UK means the pipe that takes the drain water away is the same pipe that takes the sewage out of your toilet, and because most sewage works become overwhelmed by rainfall very quickly, they have to open the combined storm overflow pipe, releasing sewage into our waterways.”
River Action UK’s E. coli testing of the waters between Hammersmith bridge and Putney in the run-up to the Oxford Cambridge boat race gave average E. coli levels of 10 times above what they should be for safe bathing, causing illness among the Oxford crew.
Regular testing of water at the newly designated bathing sites may be a move in the right direction but, warns Wardley, current testing may be inadequate. “There’s a certain amount of evidence that we should also be monitoring things like norovirus, rather than relying on E. coli bacteria, which are everywhere in the environment and not necessarily the best indicator of risks to human health.”
How to know if your local river is polluted
The Rivers Trust has produced an active map that shows where the sewage network discharges treated effluent and overflows of untreated effluent and storm water into rivers. It means you can identify and avoid entering water that’s immediately downstream of these discharges and avoid the overflows, especially after it has been raining.
“Water companies’ live monitors on their websites show where they are discharging sewage at a particular time, but it’s not just what is being discharged that is of concern, but what is already in the river,” says Watson.
When sewage goes into the river, it settles as sediment and permeates into the vegetation and incubates as a pathogen. “Bacteria and algae love heat and as temperatures rise, this pathogen is accumulating in the rivers,” notes Watson. “And without public health advice from the Government, it’s hard to know whether this makes it unsafe to swim there.”
“No river water is going to be clean enough to consume, but understanding water quality in rivers will help you identify when it isn’t OK to plunge in,” cautions Foote. “If water doesn’t smell right, it probably isn’t right. If there is scum or a film on the water, or a high level of weed and algae, it won’t be clean enough for a swim – nor enjoyable.”
If you do detect wildlife nearby, however, that’s a more positive sign. “Birds, fish, plants and insects don’t like dirty water,” says Foote, “so if you spot any, you’re in safe company.”
Algae blooms, by contrast, are bad news. According to Foote, large areas of dense floating weed and green murky water can indicate high levels of nitrates, phosphates and toxins. Blue-green algae can be toxic if swallowed, can cause skin rashes and be fatal to dogs. “It is easy to spot and often smells bad – you can taste it in the air – and it looks green and scummy,” says Foote.
Measures to take when swimming in rivers
When you arrive at the river for a swim, look at the water and use your nose. “If it doesn’t look or smell right, then regardless of what the rating is telling me, I’m not swimming there,” advises Wardley. And avoid swimming in areas where there are boats and barges that may discharge their waste into the water. “They’re not supposed to, but unfortunately it does happen,” says Wardley.
Sickness from outdoor swimming is rare, but best avoided. Avoid spending long in the water if you aren’t a good swimmer and keep your mouth firmly shut. “If you inefficiently take on water between swimming and breathing, you can be more susceptible to an upset stomach,” says Foote.
Telling youngsters to avoid getting water into their mouths when they’re splashing around can prove fruitless. “For this reason, I would not take young children swimming in freshwater bodies in this country,” says Watson.
As well as The Rivers Trust map there are a number of apps that can keep you updated on river water safety, including Magic Seaweed and Surfers Against Sewage which cover popular river areas as well as sea sewage alerts. “If there is a sewage outlet upstream of where you are planning to swim, definitely check whether it’s been discharging in the 24 hours before you want to swim there” advises Wardley.
And take precautions to prevent getting infected with Weil’s disease (leptospirosis), a rare form of bacterial infection that comes from the pee of infected animals in river water. “Cover any cuts or grazes with waterproof plasters, never swim in stagnant water and after a swim wash your hands before eating or drinking, showering as soon as you can,” warns Foote.
Symptoms to look out for after a river dip
Symptoms of E. coli after swimming include bloody diarrhoea, stomach cramps, nausea and vomiting, and usually start one to four days after you come in contact with the bacteria.
For most people Weil’s disease just involves mild fluish symptoms, but some people get seriously ill, with aches, a high temperature, headache, red eyes, nausea and diarrhoea, in which case antibiotics are needed from your GP or by calling NHS 111 for further help.
Are you better off swimming in a lido?
For those who would rather not take their chances in the UK’s rivers, lidos present an appealing outdoor swimming option, and a handful of old lidos have recently been refurbished and reopened across the UK, including Saltdean in Brighton and Albert Avenue in Hull.
There’s no doubt that, for those with young children, a lido is a safer option, because swallowing a bit of chlorine is far less worrying than river water, although there is some evidence of a link between swimming pool chlorine and childhood asthma.
But it’s infinitely less of an adventure than a river swim. “Like indoor pools, there are strict rules in a lido,” says Foote. “You only get to swim in a morning or afternoon slot, and entry is not cheap. Whereas outdoor swimming in rivers off public footpaths and public land is free. I can take a dip in between lounging in the sun or swim long and strong for hours without any need to exit the water. I see life at earth-level and it’s good for me”.
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