First of around 400 events on Tuesday, almost 4,000 rowers will attempt to earn a spot in the regatta, which has been held along the waterway since 1839.
Between May 23 and June 25, Henley and Marlow River Action Group tested the water 27 times, and on average, they discovered 1,213 E. coli colony forming units (CFUs) per 100 milliliters of water.
The Environment Agency’s inland bathing water quality regulations state that any water with more than 900 CFUs per 100 ml is unfit for swimming.
The maximum number, reported on June 19, was 25,000 CFU, more than 27 times the allowable limit, according to River Action Group, and it was left out of their report.
On June 16, the second-highest reading was 8,001.
t Fawley Meadows, where racegoers can rent hospitality huts to watch the races and the river is contaminated by effluent from the Henley sewage treatment plant, River Action tested almost half (47%) of the samples. The results showed that the CFU/100 ml was more than 900.
