A couple have criticised a water company for releasing sewage into the sea 24 hours before they went for a swim, leading to them contracting gastroenteritis.

Georgia Hearn, from Gateshead, was visiting Kent with her partner Chris and dog Sully, and they went swimming and paddleboarding in the sea at Herne Bay on Monday.

On Tuesday the three of them were struck down by a serious case of gastroenteritis, and Miss Hearn says it ruined their holiday.

Something has to change. It’s completely unacceptable

Miss Hearn complained to Southern Water about the incident and a spokesperson replied on Twitter to “apologise for the inconvenience”.

She tweeted: “I mean I’m completely disgusted at Southern Water’s response and utterly appalled about the lack of warning to tourists regarding sewage being dumped in the sea.

“If I had known I would have never have got into the sea – it’s not just myself who is poorly. It is also my partner and our dog too.

“It unfortunately has ruined our last day visiting the south coast. I’m extremely angry and frustrated about the lack of concern for public safety from Southern Water.

“There is absolutely no warning for locals or tourists about the potential risks you face by entering sea filled with raw sewage. I mean how are the water companies even allowed to dump raw sewage into the sea?

“Something has to change. It’s completely unacceptable.”

The Southern Water spokesperson who replied to Miss Hearn’s tweet said the company’s Beachbuoy app gives almost real-time updates about wastewater releases.

SOS Whitstable, a campaign group dedicated to holding Southern Water to account for its wastewater releases, asked: “Why are water companies not legally responsible for making people ill?”

Southern Water was fined a record £90 million by the Environment Agency last year after pleading guilty to thousands of illegal sewage discharges. It is not yet known whether the sewage discharge that caused Miss Hearn’s illness was permissible.

A spokesperson from Southern Water said: “Two separate releases were made on the evening of July 31 via our Swalecliffe and Gainsborough Drive outfalls. They were heavily diluted with rainwater.

“These events followed a period of heavy rainfall, over a short period of time, in a small geographical area. This resulted in a significant increase in flows from our combined surface and sewer network to our treatment works.

“They were reported on our online Beachbuoy app within an hour of them taking place.

“The resultant releases were within our Environment Agency permit, and necessary to protect homes and businesses which otherwise would have been at risk of internal flooding.

“We are working hard to reduce our use of storm overflows at Southern Water, and have a number of ground-breaking pathfinder projects working with local communities to tackle this.”