Bacteria in the Thames before the Henley Rowing Regatta

Water quality tests carried out by campaign group River Action before the race found levels of E.coli bacteria up to 27 times the permissible limit for bathing water, raising health concerns given the rising number of E.coli cases in the country.

E. coli is a diverse group of bacteria that, while usually harmless, can produce toxins that can cause serious illness.

River Action tested the water in the Henley Mile – part of the regatta course outside the Oxfordshire town – 27 times between May 23 and June 25 and found an average of 1,213 colony forming units (CFU) of E.coli per 100ml of water. In a statement on Thursday, the organisation warned the levels were “alarmingly high”.

Anything above 900 CFU/100 ml falls short of the Environment Agency’s quality standards for inland bathing water and is considered a risk to public health, the campaign group said.

More than half (47%) of the measured values ​​were above the permissible limit. The highest value was 25,000 CFU/100 ml, more than 27 times higher.

River Action also found E. coli levels up to ten times higher during tests in March.

James Wallace, CEO of River Action, accused the government and Thames Water, the water company responsible for the region’s water supply, of failing to adequately monitor water hygiene.

“This is a public health emergency. The new government must get a grip on the water pollution crisis and ensure that water companies, including Thames Water, urgently invest in upgrading treatment plants and fixing their leaky infrastructure before anyone becomes seriously ill or worse happens,” he said in a statement.

Thames Water did not immediately respond to CNBC’s request for comment, although the BBC reported that the firm called the findings “alarming” and said it would monitor bacteria levels. CNBC also contacted the government’s Environment Agency but did not immediately receive a response.

Chairman of the Henley Royal Regatta management committee and former Olympic rower Sir Steve Redgrave said the results were a “stark reminder” of the impact of sewage pollution.

“Our waterways are vital to the racing of our competitors, but also to all the athletes who train daily across the country,” he said.

Regatta organisers have advised rowers to cover any cuts and blisters and avoid swallowing river water as thousands of spectators flock to Henley on Thames for the event, which runs until Sunday.

This came as the UK has seen a rise in E. coli cases. Two people with underlying health conditions died after being infected with the Shiga toxin-producing E. coli strain (STEC). One of the deaths was “likely related” to her STEC infection, the UK Health Authority (UKHSA) said.

This particular strain is said to have been spread via lettuce leaves in ready-made sandwiches.

The UKHSA announced on Thursday that 275 cases of this variant had been confirmed as of June 25. The agency urged the population to watch for symptoms such as diarrhea, stomach cramps, vomiting and fever.