Thames Water has been carrying out river sampling at two locations in Henley to understand the conditions found in the stretch of water.

The company has been performing the tests at Marsh Lock and Hambleden Lock since May 15.

These assessments have been taking place every other day and will continue for two months.

Sampling helps to understand the quality of the river water at the specific time of the sample, but this can change even over the course of a single day.

There are many factors that can affect water quality, from agriculture runoff to bacteria from livestock.

The tests involve analysing levels of two bacteria - E Coli and intestinal enterococci.

These are indicators used by the Environment Agency to classify designated bathing waters.

It deems the 95th percentile as 'good’ - a reading above this would indicate an elevated level of bacteria. 

The Environment Agency, however, bases its classifications on samples taken over a rolling four-year period and not on individual samples.

Henley's request for designated bathing water status was unsuccessful this year.

To date, the vast majority of samples have met the threshold for ‘good’, except for two days in May and two days in June, where elevated readings were taken following periods of rainfall.

Thames Water stated that while the data provides useful public information, it should not be used to make judgments regarding the river's safety.