The grim reality of what’s lurking in the Lake District’s waters

It was a H๏τ July day and Mel Beamish decided to go for a swim in the River Brathay, high in the Langdale valley in the Lake District – it’s a remote, beautiful spot miles from the nearest town.

Mel and her friends, who’d run an ultra-marathon (36 miles) the day before, visited a popular swimming spot beside a grᴀssy bank for a cool dip.

The country was experiencing drought, and the river was low – though Mel, 38, a police detective from Cheshire, didn’t know the significance of this at the time.

Nor did she know she was swimming below a submerged sewage pipe that was discharging into the water, she told Good Health.

By that afternoon she felt sick, dizzy and gripped by stomach pains.

Initially she put it down to the race, but overnight it became far worse – ‘awful sickness, diarrhoea, delirium, sweats’, she recalls.

By the next morning she was delirious.

Her friends called an ambulance and at hospital, she was pumped full of anti-sickness drugs. Mel was discharged the same evening – too weak to stand, she had to be lifted into her van and driven home lying flat across the back seat.

When Mel Beamish, 38, decided to go for a swim in the beautiful Lake District on a H๏τ July day she had no idea that that dip would lead to her being ill for the rest of that summer

The acute illness lasted about ten days. Then came tonsillitis – ‘you can get that from sewage’, she learned later.

Mel was ill for most of that summer with ‘frequent upset stomach issues’ until September.

The hospital doctors suspected she’d been infected with Campylobacter, bacteria found in sewage, but by the time Mel saw her GP four days later it had cleared her system and couldn’t be confirmed.

Determined to trace what had made her ill, Mel sent the exact coordinates of her swimming spot to the Environment Agency – which monitors swimming water quality across England.

However, the water was tested a week too late for results to be a reliable indication of what it had been like when she was there.

Mel also contacted United Utilities, the company responsible for water and sewage across the North West.

‘I put my best detective hat on,’ she says, ‘but it didn’t really get me very far,’ she says, four years later.

Mel had previously taken her children and her dog into that same river. ‘Thank goodness they weren’t with me that day,’ she says.

As an estimated five-and-a-half million people across the UK head to the Lake District this summer for fresh air and to swim in the fabled waters of this Unesco World Heritage site, this Good Health report offers a sobering warning about the potential health risks from bacteria when bathing in UK freshwater.

Annually, millions of litres of untreated sewage are discharged into Windermere alone – England’s largest and most popular lake – carrying with it bacteria such as E. coli and intestinal enterococci.

The Daily Mail’s Will Stoddart took a trip to the Lake District to take a series of water samples and investigate just how safe the water is

These can cause vomiting, diarrhoea, and ear and skin infections; they’re particularly risky for the very young and old, who are the most likely to become seriously ill. (These aren’t the only harmful bugs in the water, but more on this later.)

Last August Olympic swimmer Hector Pardoe swam the length of the lake with a pollution sensor which showed the level of E. coli was over eight times the threshold for a safe water rating.

You don’t need to swim to get ill, it seems.

Seven-year-old Rex Earley spent six weeks in hospital – needing two emergency operations – after kayaking on Windermere last summer, where his family says he contracted E. coli.

Having seen the news stories about Windermere, last summer I took my daughters, then aged seven and five, to paddle instead in Grasmere and Derwentwater, with a boat ride on Ullswater. But is the water there safer?

To find out, I went back to the same spots ten weeks ago – but this time with sterile water sampling bottles from Simplex Health, a laboratory accredited by the United Kingdom Accreditation Service, the official body that certifies labs to the same standard used by the Environment Agency (EA).

The EA checks bathing water for two bacteria, E. coli and intestinal enterococci; it samples the water every one to two weeks from May to the end of September (the bathing season).

The agency tests official designated bathing spots, but there are only eight such spots in the whole Lake District – four on Windermere, three on Coniston and one on Derwentwater.

And many visitors don’t use just these spots.

‘There are people swimming in Grasmere and many other lakes and rivers in the Lake District that are not officially designated bathing waters,’ says Ben Surridge, a senior lecturer in environmental science at Lancaster University. ‘So there will be no official monitoring of them.’

Without that testing, he says, you won’t know whether the water is safe or not.

And what many people may not realise is that nearly every lake in the Lake District has a sewage works discharging waste into it from nearby towns.

Annually, millions of litres of untreated sewage are discharged into Windermere alone, carrying with it bacteria such as E. coli and intestinal enterococci

You’re unlikely to spot them as they rarely sit on the lake shore.

Some discharge into the becks and rivers that feed the lakes, sometimes miles upstream. Others disperse their contents through outfall pipes laid underwater.

Every lake in the Lake District carries some form of pollution, says Louise Lavictoire, head of science at the charity the Freshwater Biological ᴀssociation.

This is not just from water-company discharges, she explains: ‘There are countless private discharges which range from septic tanks that are emptied regularly to cesspits and small package treatment works.’

Indeed, there are 1,800 private cesspits from homes, H๏τels and campsites emptying into Windermere alone, according to United Utilities.

The problem is these private cesspits ‘don’t have the technology to kill bacteria like E. coli’, says Matt Staniek, a zoologist and founder of the campaign, Save Windermere.

The issue with water quality is two-fold – first, storm overflow.

Sewage is the dirty water that drains from our homes – from loos, sinks, baths, showers and washing machines.

It carries human urine and faeces, along with the soaps, detergents and grease that go down the plughole.

Sewer pipes also carry rainwater from roads and roofs, and in heavy rain the two surge into the works together.

When more arrives than the works was built to handle, a storm overflow – a type of gate – opens and lets untreated sewage and rainwater into rivers and lakes.

Even ‘treated’ waste isn’t free of bacteria. A sewage works removes the solids and breaks down the waste, but won’t kill bacteria unless fitted with an ultraviolet (UV) light lamp – and most Lake District works don’t have this.

Demand on the sewage system during the summer is greater, with the Lake District incredibly busy at this time and sewage works under the most strain as a result

The EA says these are only required where a lake has a designated bathing water site, and even then only if the agency considers the risk of contamination high enough.

At Coniston, for instance, the village sewage works has no UV stage to kill the bacteria: and it discharges into Church Beck – which empties 50m further on, directly into a designated swimming area on the lake (at the boating centre where children swim all summer). This site was rated ‘poor’ in 2024 and only scraped up to ‘sufficient’ in 2025.

Even the sewage works that do have UV aren’t failsafe.

Matt Staniek says he has operator log books for the Lake District ‘where the operators are saying that the UV dosing is failing because of fast flow rates’ (in rainy weather the sewage flow speeds up past the UV lights).

UV lights also only work if the bulbs are kept clean and replaced, he adds. If not, ‘you just get a layer of excrement that dries on the bulbs and it makes it ineffective’. (United Utilities say the system is designed to adjust to flows as required.)

What many visitors won’t know is that bacteria levels peak during the summer months – according to The Big Windermere Survey, a two-and-a-half-year study by the Freshwater Biological ᴀssociation and Lancaster University, published in 2025 – leading to ‘an increased risk of gastro-intestinal illness if water is ingested’.

During warm, dry weather rivers are generally low, which means there is less water to dilute the treated sewage – a problem highlighted earlier this year by the chief medical officer Professor Sir Chris Whitty, who said while storm overflows are a well-known issue, there’s less public awareness of the risks from discharge from waste water treatment works that are operating within their permitted levels, yet where water levels are low.

This occurs at the times of year ‘when the great majority of children and adults tend to use water environments’, he warned.

This is when Mel Beamish swam.

Add to this the greater demand on the sewage system during the summer – as anyone who’s been there knows, the Lake District is incredibly busy at this time, when sewage works are under most strain, says Louise Lavictoire, with ‘significant challenges’ from extra visitors, all flushing loos and running showers, pouring into works built for small local populations.

At picture-postcard Grasmere, for instance, the sewage works now pumps out far more than it was ever meant to, says Matt Staniek.

United Utilities reports a maximum summer population of about 2,700 for Grasmere.

The water industry works on the basis that we each produce about 150 litres of wastewater a day, so the works should be dealing with around 405,000 litres on a busy summer day.

But average flows entering the works are around nine times higher in the summer, according to an analysis of the company’s own figures, by the campaign group Windrush Against Sewage Pollution – with the volume of treated sewage leaving the works regularly topping six million litres a day in 2024 and 2025.

While it is perfectly legal to discharge untreated sewage into the water in certain circumstances, how often this happens is deeply worrying, as Good Health discovered using a combination of Freedom of Information requests and analysis of EA publicly available records.

It might look clean but is it? Last year alone, raw sewage was discharged into these four lakes (ie, excluding Windermere) for over 3,200 hours, including during the bathing season. A ‘spill’ is a single discharge from a storm overflow.

Coniston (sewage works discharge into Church Beck, which feeds into the lake by the Boating Centre): 131 spills over 1,765 hours in total.

Grasmere (discharge goes straight into the lake): 53 spills, 408 hours.

Ullswater (discharge goes into Glenridding Beck then into the lake): 82 spills, 144 hours.

Derwentwater (Keswick sewage works discharges via River Derwent): 77 spills, 907 hours.

Source: Environment Agency event duration monitoring data

Using EA records for last year, we found that the storm overflows (known as ‘spills’) at Coniston, Grasmere, Ullswater and Derwentwater opened more than 340 times, releasing water containing raw sewage into the lakes and becks, for over 3,200 hours.

The annual figures for the Glenridding sewage works (which discharge into the beck that flows into Ullswater) were the worst in the five years analysed, up from 38 spills lasting 43 hours in 2024 to 82 spills lasting 144 hours last year. 

At the Grasmere sewage works, which discharges directly into the lake, spills lasted 408 hours (see box, right).

Some storm overflows included hundreds of hours during the summer bathing season. 

At Coniston, the Church Beck overflow (which feeds into a designated bathing spot) was open for 489 hours between May 15 and September 30 (out of a total 1,765 overflow hours for the year).

Bathing season overflows at the Keswick sewage works, which discharges into the River Derwent (which feeds into Derwentwater), lasted for 183 hours.

Using a storm overflow is legal, but is meant to be a last resort – and only in wet weather.

Yet among those bathing-season discharges was a worrying number of suspected dry-day spills, when untreated sewage was released despite little or no significant rainfall (meaning there’s even less water to dilute any bacteria). These are not legally permitted.

For instance, last year Coniston had six ‘dry-day’ spills – that lasted in total almost 56 hours – in the bathing season.

At Grasmere, the sewage works discharged on dry days for 71 hours and 50 minutes between January 9, 2024 and January 7 this year.

Visitors also need to know that while the water at bathing sites is checked for E. coli and intestinal enterococci, these ‘do not tell the whole story’, Professor William Gaze, an environmental microbiologist at the University of Exeter, told Good Health.

He says the same sewage can carry viruses such as norovirus and hepatitis, and parasites such as giardia, which brings on weeks of debilitating diarrhoea.

There may be another potential risk. Researchers at the University of Exeter have previously found that surfers are three times more likely to carry bugs that are resistant to antibiotics and they are now investigating freshwater swimmers. Drug-resistant infections can be harder to treat, suggests Anne Leonard, an environmental microbiologist at Exeter, who has studied this problem in swimmers.

She adds: ‘In designated bathing waters with good water quality classifications, we can expect the risk to be relatively low for most people.

‘But children can be at a greater risk because they spend more time in the water, tend to swallow more water when bathing – and may not have well-developed immune systems.’

So what happened when I sampled the water at three lakes my family used last summer? The water certainly looked perfectly clear.

Grasmere, one of the smaller lakes, is not a designated bathing site but this idyllic lake made famous by Wordsworth has a shingle beach that’s popular with families.

Since 2020, the sewage works have put more than 12 billion litres of treated sewage into this ‘tiny body of water’, says Matt Staniek. You can’t actually see where this goes in, as the outfall discharges on the bed in the middle of the lake.

Lab results from the sample I drew from the water’s edge showed it contained E. coli.

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At pristine-looking Ullswater – also not a designated bathing site, though I saw people paddling – I waded up into the stunning Glenridding Beck and held a bottle directly under the pipe that emerged from a small sewage treatment plant I’d discovered behind some trees on the bank.

The sample showed E. coli and intestinal enterococci.

At Crow Park on Derwent Water, which is a designated bathing site, the results revealed E. coli and intestinal enterococci.

My samples at Grasmere and Crow Park were reᴀssuringly low (one ‘colony forming unit’ of viable bacteria of E. coli and intestinal enterococci per 100ml).

But at Ullswater it was 57 E. coli per 100ml and 36 intestinal enterococci per 100ml – the bathing limits are 500 per 100ml.

The samples were also tested for coliforms, another type of bacteria that live in the guts of humans, animals and birds – there were 1,986 per 100ml at Ullswater.

The EA rated Crow Park as ‘poor’ in both 2024 and 2025, with official advice against bathing, while a sample on July 30, 2025 recorded 1,300 E. coli and 750 intestinal enterococci per 100ml, indicating heavy contamination.

So does my experiment mean I shouldn’t have worried about Grasmere and Crow Park?

No, suggests Ben Surridge, who led the Big Windermere Survey (where volunteers collected water samples from across the lake), as water quality ‘can change really rapidly’. 

A heavy downpour, for instance, can send pollution surging into a lake within hours, so a reading taken on a dry morning tells you nothing about the afternoon after rain.

Before their trip, Rex Earley’s family had checked on the EA website which showed water quality at Windermere was ‘excellent’ (although not at an official bathing spot, they set off from a popular kayaking centre where ‘lots of people were swimming and paddling’, Rex’s mum later said).

And some people may become ill at even low levels – the World Health Organisation, whose research was the basis of bathing-water standards, says that water classified as ‘good’ carries a 3 to 5 per cent risk of gastroenteritis per bathing exposure, potentially as high as one case for every 20 visits to the water.

And as Anne Leonard points out children can be more vulnerable. ‘The true toll is unknown because most people never connect the illness to the water,’ she says.

‘They go home, fall ill several days later, and blame their symptoms on any of a range of other possible sources, such as food, household contacts, or contact with animals.’

Indeed when Peter Semple, a hospital anaesthetist from Leeds, caught Campylobacter he says from swallowing water after swimming in Windermere in 2022 (he was the only one in his group who swallowed the water, and the only one who fell violently ill), his doctor blamed undercooked chicken – until the anaesthetist pointed out he was a vegetarian.

Whether it’s safe to swim in the Lake District is a conversation no one should be having at all, says Matt Staniek. ‘It should be somewhere that is absolutely pristine.’

A United Utilities spokesman said: ‘We understand concerns about storm overflows, which is why we are investing £1billion across Cumbria by 2030 to improve rivers and lakes.’

The company added that, recognising the growing impact of climate change, including more extreme rainfall and rising temperatures, it is working with a range of experts ‘to evaluate options that would result in only rainwater entering Windermere’.

How to protect your family 

Environmental microbiologist Anne Leonard suggests the following:

Check before you go: use the Environment Agency’s Swimfo site to identify designated bathing water spots and their latest rating. The free Safer Seas and Rivers Service app delivers live alerts including sewage spills, across a range of designated bathing sites. For United Utilities’ storm overflow map go to unitedutilities.comAvoid swimming at sites not designated for bathing.Even at official bathing sites, avoid swimming for 48 hours after heavy rain, when storm overflows are most likely to have spilled.Avoid obvious inflows – pipes, drains and the mouths of becks – and anything cloudy, foamy or foul-smelling.Cover cuts and grazes before getting in, and wash hands (or use anti-bacteria hand gel) afterwards.