HIGH levels of pollutants have been found in the River Frome, which passes through Chipping Sodbury and Yate, in sampling by ‘citizen scientists’.
Every summer the Bristol Avon Rivers Trust asks volunteers to collect samples from waterways across the region to test them for common pollutants, including phosphates and nitrates.
This year more than 130 volunteers collected 202 samples in early July as part of the ninth RiverBlitz campaign.
The results have been published online by BART, which found that high levels of both nitrate and phosphate pollution were found at a site known as the Frome Headwaters, behind Wickham Close in Chipping Sodbury.
The site was the furthest upstream that a test was carried out this year on the Frome, which rises on the private Dodington Park estate owned by Sir James Dyson.
At Wickwar Road in Chipping Sodbury, medium levels of the nutrient pollutants were found, along with invasive Japanese knotweed plants and plastic bottles.
Medium levels of nitrates and low levels of phosphates were found at the footbridge in Tyndale Avenue Park, but at Cog Mill, near Iron Acton, high levels of both nutrient pollutants were found, along with plastic bottles and takeaway cartons.
Volunteers clear huge quantities of dumped rubbish
The survey results were published as Upper Frome Friends, a volunteer group which organises sessions cleaning up the river, revealed the latest haul of dumped rubbish (pictured above).
The haul included bikes, furniture, traffic cones and signs, tyres, carpet, clothing, plastics and a shopping trolley.
To help out, join the Upper Frome Friends Facebook group or email riverfromereconnected@southglos.gov.uk
BART says nutrients, particularly phosphates and nitrates, are among the most common pollutants of freshwater worldwide and are widely used as indicators of water quality.
Although they occur naturally in healthy rivers, high concentrations lead to harmful algal blooms which can harm other plant life and fish.
High levels are caused by pollutants including fertilisers, manure, sewage, urban surface water run-off and household products like detergents.
Across the region, BART said 69% of samples had high nutrient loads of phosphate and nitrate combined, with 3.5% recording low nutrient levels.
However, this was an improvement on last year, when 88% of samples confirmed high nutrient loads and only one out of 290 samples showed low nutrient concentrations.
Pollution ‘impacts water quality and wildlife’
BART chief executive Simon Hunter said: “The Bristol Avon RiverBlitz provides a snapshot of the catchment’s water quality during a week in July.
“While it may not offer detailed insights into individual streams, the expanding dataset from multiple years reveals trends across the catchment.”
He said that across the region, high pollutant levels were recorded along the Bristol Frome, River Trym, and the Avon between Bristol and Bath.
Other areas with high nitrate levels included the Avon between Bristol and Bath, the lower Bristol Frome, south Bristol streams and most sites on the Trym, with only 5% of samples showing low nitrate levels.
Mr Hunter said: “The data collected suggests, during the week of the Bristol Avon RiverBlitz, that nutrient pollution is likely impacting water quality and, consequently, the health of some watercourses and wildlife across the Bristol Avon.”
He said this year’s milder summer may have resulted in lower nutrient levels than in the previous two years’ surveys, adding: “It’s important to note that the Bristol Avon RiverBlitz captures water quality measurements at a specific moment in time, and there are several other parameters we did not test that could also impact river health, such as bacterial and chemical readings.”
To view figures from the survey visit bristolavonriverstrust.org/riverblitz.