High levels of dangerous bacteria has been found in popular Oxford river swimming spots.

Weekly testing of water from the River Thames at Wolvercote, Port Meadow, Longbridges and Kennington Meadows has shown that the water periodically contained high levels of E coli. bacteria over this winter between January and March this year.

The bacteria found in the river can be linked to faecal matter which could be from excrement from sources such as storm overflows, agriculture and wildlife. However, contact with high levels of bacteria can be harmful to human health, linked to stomach upsets and other diseases.

At each of the four locations, E. coli levels exceeded the threshold level for ‘sufficient’ bathing water quality three weeks out of ten. This means if the areas would be given a ‘poor’ rating if they were formally designated as bathing water areas.

Thames Water funded and analysed the samples in order to support efforts for a designated bathing water area in Oxford. The sampling will continue over the spring and summer months, and the results will be released for swimmers weekly.

Tim Harris, associate at the Rivers Trust said: “We don’t know for certain whether these levels of bacteria are from raw sewage or other sources like agriculture - to know that, we need to wait for a few more months of results. However, this data indicates that, if you swam in the river this winter and swallowed some river water, you could have had an unpleasant dose of E. coli.”

Read also: Thames Water sewage discharge sparks public swimming concerns

These results come after open water swimmers and councillors asked Thames Water to come clean about releasing sewage in the River Thames. In 2019, there were 83 discharges of sewage in Oxford according to Thames Water, but many say this figure is not acceptable.

Richard Aylard, Sustainability Director at Thames Water said:“These results are not unexpected during a period of wet winter weather - it will be interesting to see whether there is a change as things get warmer and dryer and the flow in the river reduces. In the longer term our major investment in additional treatment capacity at Oxford sewage works will make a difference, and in the meantime our trial of discharge notifications should help local people to make informed decisions about going in the water.”