Just four of 45 sites on the River Ure were found to be safe enough for bathing during a recent water sampling exercise.

The 74-mile Ure is the main river in Wensleydale and also flows through Masham, Ripon and Boroughbridge.

Concerns about water quality led to the creation of the Stop Ure Pollution campaign group, whose volunteers helped conduct two rounds of sampling along the entire length of the river.

The first took place after a dry period on August 21 and the second occurred after heavy rainfall, when some of Yorkshire Water’s combined storm overflows had been discharging, on October 9.

Yorkshire Dales Rivers Trust, a Pateley Bridge charity that aims to improve rivers, said 20 of the 45 sites tested on the Ure and its tributaries in August had concentrations of the faecal bacteria E.coli above the level deemed sufficient for bathing water, which is 900 colony-forming units per 100 millilitres of water.

On October 9 only four sites were below the safe limit.

E.coli concentrations were high from the top of the catchment at Lunds until West Tanfield. They dropped slightly at Boroughbridge before rising dramatically at Aldborough, which recorded 9,500 cfu per 100ml, which is more than 10 times the safe limit.

Besides Aldborough, particular areas of concern included the Skell, which flows through Ripon, Bishop Monkton and the Tutt, which passes Nidd and Scotton.

Professor Richard Loukota, chairman of Stop Ure Pollution, said: 

Further analysis of the results, along with other work to increase understanding of what is causing the heightened E.coli levels in the Ure catchment, is expected to take place.

The Skell and Tutt tributaries will be a particular focus due to their high readings.