High levels of E coli found at Henley days before international regatta

Thames Water has said it is not the cause of increases in bacteria in the river, where thousands of rowers will compete in the Henley Royal Regatta. Photograph: Jill Mead/The Guardian

Harmful E coli bacteria have been found at very high levels at Henley, days before elite rowers compete in the international regatta there.

Water quality testing in the Henley Mile, part of the regatta course outside the Oxfordshire town, has revealed mean levels of 1,213 E coli colony forming units (CFU) per 100ml of water, across 27 tests. Where E coli levels are above 900 CFU/100ml, the water quality is deemed poor, according to bathing water designations, and is a threat to public health.