Dangerous levels of E.coli have been found at one of Kent’s busiest beaches - with the number of colonies of the bacteria in the water increasing 12-fold in a matter of weeks.

Standard water quality testing samples, carried out 20 times a year between May and October, found the shocking results in the most recent set of tests.

Carried out on August 29, results found 1,800 colonies/CFU (colony forming units) per 100ml of water were found when testing for E.coli, compared to 150 CFU when last tested in mid-August.

The presence of the bacteria in the waters at Dymchurch comes as a do not swim warning remains in place for nearby St Mary’s Bay over fears of poor water quality.

A warning was issued in February setting out the no swim zone and the investigation launched into where bacterial matter was getting into the water.

Tony Hill, KCC councillor for Romney Marsh, vowed to press the authorities involved on the matter but was reluctant to offer any conclusions based solely on the latest spike.

“Anything could be causing the spike, we’ve seen Southern Water testing before to see if the E.coli is from animal or human faeces,” he said.

“I’m loath to advise people not to go to the beach or go swimming until we’ve had a chance to really analyse what’s going on and you do get spikes, it can be one random sample, it’s not concerning.

“It’s a topic I’m passionate about, a lot of our water quality is better than people think but people on social media say one thing when actually it’s not quite like that at all.

“But we will take it very seriously and if there’s been any failings we will investigate this.

“We’re in regular contact with Environment Agency and Southern Water to monitor matters, we get involved with all sorts of things to do with water.”

The bacteria Escherichia coli is commonly found in the lower intestine of warm-blooded organisms.

E.coli in water is a strong indicator of sewage or animal waste contamination though it is widely accepted other causes for the bacteria’s presence exist - with Southern Water claiming no sewage had been released in the sea at the time of the tests.

Most types of E.coli are harmless and even help keep your digestive tract healthy but some strains can cause diarrhoea if you eat contaminated food or drink-fouled water.

Guidance from the Environment Agency states the presence of E.coli bacteria could be caused during heavy rainfall in which soil potentially containing the bacteria is washed into rivers, streams, lakes or groundwater.

Between 2018 and 2022, the bathing water quality at Dymchurch was classified as good - with less than 500 colonies or CFU per 100ml required to achieve this ranking.

In the past five years, the number of colonies of E.coli per 100ml of water at Dymchurch has never exceeded 1,000 CFU.

The latest rating officially rates the quality as poor and “the water has not met the minimum standard” for safe bathing.

In microbiology terminology, a colony-forming unit (otherwise known as a CFU or the number of colonies) is a precise unit used to estimate the number of bacteria or fungal cells contained within any particular sample.

‘Once a poor classification has been given, it is legally required to remain in place until the next set of bathing water classifications are available – November 2023...’

Findings of intestinal enterococci (IE), also used as indicators of the presence of faecal matter in water, also rose dramatically with an increase of almost 1,000%.

When asked about the issue at Dymchurch and if it could close the beach in response, the Environment Agency said it does not close beaches but does offer advice against bathing in them.

In a statement to KentOnline, a spokesman said: “St Mary’s Bay received a ‘Poor’ bathing water classification following elevated results during the 2022 season.

“Once a poor classification has been given, it is legally required to remain in place until the next set of bathing water classifications are available – November 2023 – regardless of the quality of samples taken during the 2023 season.

“The results for Dymchurch taken on August 29 showing 1,800 colonies per 100ml of E.coli and 1,500 colonies per 100ml of Intestinal Enterococci are of concern and we are investigating the cause.”

EA also noted samples taken at bathing waters take four to five days to analyse and as such it does not issue advice against bathing in response to a high result as it is not necessarily reflective of the current situation.

A Southern Water spokesperson said: “We are a key steward of coastal water quality but far from the only one.

“We are working with the Environment Agency and other stakeholders to understand the causes of high samples at Dymchurch.

“There are no CSOs [Combined Sewer Overflows] in that area which can influence water quality. Water quality can be affected by many factors such as agricultural and road run off and wildlife.”