The UK's official swimming rivers are too polluted to swim in

There are close to 1500 rivers in the UK, but just two stretches have been officially approved as swimming destinations – and even these are currently too polluted to use safely. While campaigners hope that other rivers will soon receive this “bathing status” designation, some fear the label is misleading, as there are few requirements to clean up pollution that can harm health and the local ecology.

Environmental matters are devolved in the UK, meaning the UK government oversees bathing waters in England, while Scotland, Wales and Northern Ireland govern their own affairs.

More than 400 bathing waters in England are tested by the UK’s Environment Agency (EA) for levels of Escherichia coli, which causes diarrhoea, and intestinal enterococci, which are linked to urinary tract infections.

These tests occur 20 times at each site during the “bathing season” of mid-May to the end of September. Most are beaches, with just two stretches of river: the Ilkley bathing site on the river Wharfe in West Yorkshire and a stretch of the Thames in Oxford. No other UK nation has designated bathing rivers.

Based on its measurements, the EA categorises bathing waters as either excellent, good, sufficient or poor. Last year, 93 per cent were deemed excellent or good, but the two rivers were rated poor. Swimming is still permitted in them, but officials have had to put up signs advising people against doing so.

Part of the problem is that applications to grant bathing status don’t require any water quality test, with tests only taking place once the status has been given. Given the generally poor state of England’s rivers, newly granted rivers are likely to be in poor health. In fact, the sole requirement, set by the UK Department for Environment, Food and Rural Affairs, is that the water has “a large number of bathers in relation to any infrastructure or facilities that are provided”. In other words, the water can receive bathing status even if people are swimming in pollution. New Scientist asked the EA why it doesn’t test for other pollutants, but it declined to comment.

Richard Tyler at the Save the Wye coalition, a campaign group aimed at improving the water quality of the UK’s fourth longest river, says he fears the general public don’t understand the distinction between a river’s bathing status and its ecological status. “Just because it is safe to swim in a river does not mean it cannot still be polluted,” he says.

Cleaning rivers takes time. Ilkley only gained bathing status in 2020, the first stretch of English river to do so, with the Thames in Oxford following in 2022. The poor state of these rivers is probably due to sewage discharges and pollutants from farms allowing bacteria to flourish, says Alistair Boxall at the University of York, UK.

Creating accountability

Ruth Leach is leading a campaign to get bathing status for a stretch of the river Deben, Suffolk, in the hope that it will be monitored and cleaned by the EA and Anglian Water, the firm responsible for wastewater treatment in the region. “It’s about creating some accountability and opening water firms up to scrutiny,” she says.

Anglian Water says it supports the campaign and, after speaking to Leach, it is testing the Deben once a week for E. coli and intestinal enterococci levels. “As part of our Get River Positive programme, we’ve pledged to make sure our operations will not be the reason for poor river health,” a spokesperson said. New Scientist understands the EA is expected to make a decision on the Deben’s status in time for this year’s bathing season.

But Tyler says that simply measuring bacteria in a water body isn’t sufficient. For example, phosphorus, which can leak from local farms, has little direct impact on human health and is rarely monitored in bathing waters. Yet it is a major issue for rivers, as it leads to increased algal growth. This can lower oxygen levels in rivers, harming local animal and plant life, says Tyler, and some algae can be dangerous for people.

Boxall says the EA also doesn’t monitor for domestic pollutants, such as medicines and shampoos, which can end up in rivers. “We’ve done research that shows that ibuprofen levels in half of England’s rivers may be harming fish health,” he says.

Rivers in highly populated urban areas of England also appear to contain high levels of antibiotics, says Boxall, but there is no requirement to test bathing waters for their presence. “There is some suspicion that river systems could be contributing to the antimicrobial resistance crisis,” he says. “But there are no limits on how much antibiotics can be emitted from wastewater treatment works into rivers.”

Some river campaigners have moved away from seeking bathing status. Susan Buckingham at the Friends of the Cam says her team didn’t back moves by other local activists to seek bathing status for part of the river Cam in Cambridge. “Our reason for being is to make rivers clean and to get freely flowing rivers, but actually having a bathing quality designation is sort of meaningless,” she says.

When asked whether people can confidently swim in rivers with bathing status, the EA declined to comment. But there is some evidence that designating bathing waters and monitoring them for bacteria makes them safer for humans to swim in. Nick Voulvoulis at Imperial College London points out that many of England’s coastal bathing waters were in a far worse state several decades ago. According to the EA, just 28 per cent of bathing waters met the highest standards in force in the 1990s. Today, the figure is 72 per cent – though it is hard to make direct comparisons, as 2015 saw stricter guidelines introduced.

Ensuring that rivers with bathing status have lower E. coli and intestinal enterococci levels is likely to require the installation of more wastewater treatment facilities, says Voulvoulis. Such plants are expensive, but this is how water quality at coastal sites was improved, he says. Last year, ultraviolet disinfection measures were added to the wastewater plant near the Ilkley bathing spot, with the hope that it will lower the levels of microbes released by the plant into the river Wharfe.

To make rivers truly pollutant free, bathing status can only be the start, says Boxall. Taking pharmaceutical pollution as an example, he notes that new cosmetics often aren’t rigorously tested for their effect in water bodies. “We could redesign those products to make them safer for the marine environment,” he says.

Meanwhile, Tyler argues that the best way of solving the Wye’s phosphorus problem would be to deal with chicken manure from nearby farms, which last year were found to be one of the main sources of phosphate pollution in the river.

Each polluted river in England is likely to have a unique set of problems, so each will require a unique set of solutions. But Jamie Woodward at the University of Manchester, UK, argues that to solve any of these problems, we first need detailed river-monitoring schemes, beyond a simple focus on bacteria. “In environmental stewardship terms, I would say we’re a failed state right now,” he says. “We don’t even have the data to say how bad we actually are.”