Sewage is scaring wild swimmers out of the water

Louise Prime swims all over South East England

Wild swimmers across the South East say they have stopped getting in the water due to fears over pollution.

People who swim in Surrey rivers and the sea off the Sussex and Kent coasts say they think swimming has become "dangerous".

A BBC investigation found that Thames Water and Southern Water have potentially spilled sewage on days when it was not raining, despite this being illegal.

Southern Water said the pollution issue had "greatly improved" over the last 10 years, while Thames Water said it was "committed to seeing our waterways thrive".

Sholto Silvestri and his wife Marisa Dixon used to swim in the rivers around Thames Ditton, Surrey, almost every day.

“It was just the most beautiful feeling,” Mr Silvestri told the BBC. “I was swimming a mile upstream and then coming back with the tide. It was very calming.”

Mr Silvestri said he was worried wild swimming was jeopardising his health

However, he said the couple stopped because they came home smelling of "diesel or really stinky stuff” and Ms Dixon had become ill after a swim.

“I realised exactly how dangerous it is,” added Mr Silvestri.

In May, a team of the UK's top engineers and scientists warned of the growing public health risk from human faeces in the country's rivers, and called for more regular testing.

Senior lecturer in environmental sciences at the University of Brighton Dr Diogo Gomes Da Silva told the BBC certain strains of E.coli carry a “high risk” of causing infections, gastroenteritis and diarrhoea.

Danielle Kaelin from Henfield, West Sussex, has an app that monitors pollution and warns her when she should avoid swimming.

She said these alerts meant she and her friends continually had to abandon their training for a charity swim across the English Channel - a feat they completed in July.

"Because swimming is a major part of our life it's really rubbish... [when] the sea is suddenly out of bounds," Mrs Kaelin said. "It's ridiculous."

Dr Da Silva suggested people could reduce the odds of getting sick by not swimming after heavy rainfall and avoiding swimming in autumn and winter, when levels of untreated sewage are higher in rivers and seas.

Danielle Kaelin said explaining the situation to Swiss relatives was "embarrassing"

Louise Prime, who swims in the St Andrew’s Lakes near Rochester, the sea off Kent, including Margate's tidal pool, and Surrey's rivers, said she was continuing to swim despite the threat of sewage.

However, she said she would like to see "much tougher legislation and effective fines" to combat pollution.

“The infrastructure needs to improve - there's a lot of profit made by water companies,” said Mrs Kaelin.

“I know they say they are putting in more money, but the proof is in the pudding. At the moment, no-one's seeing anything get better.”

Southern Water chief executive officer Lawrence Gosden received a £183,600 bonus this year, despite the utility firm proposing an increase of 73% to household bills over the next five years.

Graffiti in Margate, Kent, highlights pollution in local seas

Southern Water said the pollution issue had "greatly improved" over the last 10 years, citing “significant advances in treated water quality, a reduction in overall pollution numbers, and falling customer complaints".

“Since 2020 we have spent £157m in improving our wastewater treatment in Sussex with a further £137m allocated for the year ahead," it added.

Thames Water told the BBC it had an "ambitious business plan" that proposed spending £19.8 billion to meet "customers’ priorities".

“We are committed to seeing our waterways thrive, but we can’t do it alone," it added. "Farming, industry, road runoff, wildlife and increasingly extreme weather also play a role in river health."

The government has announced plans to make water company bosses criminally responsible for breaking water quality laws, plus bans on bonuses if environmental standards are not met.