High levels of pollution found in river Frome
A SURVEY by "citizen scientists" to test the health of the river Frome found high levels of pollution in more than half of samples.
Charity the Bristol Avon Rivers Trust recruited 193 volunteers to take part in water quality testing in local streams and rivers across the region in its WaterBlitz event.
At events held during July, including one in Oldbury Court, volunteers were given sample kits to test for nutrient pollution and also asked to note the colour of the water and whether algae, oil or litter could be seen.
Their results, which have now been analysed and published, show levels of pollution on the rise.
A total of 47 samples were taken from the river Frome – which flows through the Fishponds area on its way from its source near Chipping Sodbury to Bristol's Floating Harbour – and its tributaries.
Of these, nine were taken from Frenchay, Fishponds, Stapleton and Eastville.
High levels of nitrate or phosphate nutrient pollution were found in Frenchay, Vassalls Park, Begbrook Park, opposite Blackberry Hill, and in Eastville at Cottrell Road and near Ikea.
Medium levels of pollutants were found at Snuff Mills and Eastville Park.
Litter was also found in the water in Eastville and in Vassalls Park, while algae was found in Oldbury Court and oil in Eastville.
Overall, 53% of samples from the river showed a high level of nutrient pollution, while 34% showed a medium level.
Bristol Avon Rivers Trust project manager George Clark said: "Nutrients, particularly phosphates and nitrates, are amongst the most common pollutants of freshwater across the world. As a result of their wide-ranging effects, levels of phosphate and nitrate are widely used as indicators of water quality."
He said that the results showed a "significant increase" in the proportion of samples showing high nutrient pollution, from around 1 in 5 last year to more than half 12 months later.
High nutrient levels can affect wildlife and cause a decline in water quality, making it less safe, because they encourage plant growth, in particular algae which uses up the oxygen in the river and blocks out light.
George said that the causes of high nutrient levels included: agricultural pollution from livestock or fertilisers; garden pesticides and fertilisers washed into our rivers, especially through the drainage network; combined sewer overflows (CFOs) used to provide relief to the sewer system and prevent homes from flooding during periods of heavy rain.
He said: "Unfortunately, when CSOs kick in, rainwater mixed with raw sewage, containing nutrients such as phosphate and nitrate, is discharged into our rivers."
The project was funded by bodies including Bristol Water, Wiltshire Wildlife Trust and the People’s Postcode Lottery.
More information on the results can be found online at bristolavonriverstrust.org/waterblitz and anyone who wants to volunteer or ask questions about the project should email firstname.lastname@example.org.
Picture: Collecting samples for testing. Photo courtesy of Bristol Avon Rivers Trust