Oxbridge Boat Race rowers warned of E coli in River Thames - ‘alarmingly high’ levels

A campaign group has found “alarmingly high” levels of E coli bacteria along the stretch of the River Thames used for this weekend’s Oxbridge boat race.

The bacteria, which can cause a range of infections via contaminated water, was discovered by River Action and the Fulham Reach Boat Club between February 28 and March 26.

The 16 tests carried out around Hammersmith Bridge indicated an average of 2,863 E coli colony forming units (CFU) per 100ml of water. To meet bathing water quality standards, this level should be below 1,000 CFU per 100ml.

River Action also recorded its highest level of 9,801 CFU meaning it was nearly 10 times higher than levels found in bathing waters graded as "poor" by Environment Agency standards.

The government advises against bathing in such waters, with "poor" being the worst out of the four classifications.

River Action said the testing locations suggest that the source of pollution is from Thames Water discharging sewage directly into the river and its tributaries.

According to publicly available data, by March 26 Thames Water had discharged sewage into the Greater London area of the River Thames for 1,914 hours since the start of 2024, equivalent to 79 days. The data comes from 40 storm overflow sites between Kingston and the mouth of the river in the east.

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On Saturday March 30, the Gemini Boat Race between Oxford University and Cambridge University will take place and students are set to row across the stretch of the River Thames where the E coli was found.

Due to the proximity of the polluted water, British Rowing, River Action and The Rivers Trust have developed a set of guidelines for rowing on poor quality water.

Tips to rowers include covering cuts, grazes, and blisters with waterproof dressings, taking care not to swallow river water that splashes close to the mouth, wearing suitable footwear when launching or recovering a boat, and cleaning all equipment thoroughly.

CEO of River Action James Wallace said: “We are in a tragic situation when elite athletes are issued with health guidance ahead of a historic race on the capital’s river. Our water quality results show what happens after decades of neglect by an unregulated water company, Thames Water.

“For the safety of river users everywhere, rowers, communities and conservationists are uniting to ask the Government to enforce the law and to prosecute polluters. River Action wants water companies to honour their commitments to the regulators and bill payers by investing in their infrastructure and stop dumping sewage. Everyone should be able to enjoy our rivers and seas without risking their health.”

CEO of Fulham Reach Boat Club Adam Freeman-Pask said: “High levels of E coli match the trend of organic pollution found through our citizen science water quality testing. This data must serve as a wake-up call for policymakers, regulators, and water companies. The river is a lifeline for Londoners’ health and wellbeing, which we need to protect. We welcome the new guidance to help us enjoy the river safely.”

A Thames Water spokesperson said: “Taking action to improve the health of rivers is a key focus for us and we want to lead the way with our transparent approach to data. We remain the only company to provide live alerts for all untreated discharges and this ‘near real-time’ data is available to customers as a map on our website and is also available through an open data platform for third parties, such as swimming and environmental groups to use. 

“We have experienced higher than average long-term rainfall across London and the Thames Valley with groundwater levels exceptionally high for the time of the year. The overflows are designed to operate automatically when the sewer network is about to be overwhelmed which then releases diluted wastewater into rivers, rather than letting it back up into people’s homes. 

“We are working hard to make these discharges unnecessary and have published plans to upgrade over 250 of our sites, including a £100 million upgrade of our Mogden sewage treatment works in South West London to treat the high volumes of incoming sewage and reduce the need for overflows during wet weather.”