Testing for E.coli in our rivers
How it began
In 2022, amid growing national concerns about our contaminated waterways, Babergh Green Party members organised a walking protest in Sudbury and a day of river action in East Bergholt.
‘Stop the Poo’ protestors on Friars Meadow in Sudbury, August 2022
River action day in Flatford, September 2022
In conjunction with this, BGP took the decision to fund the sampling and testing of various rivers in the district. An incubator, E.coli testing plates and test tubes were purchased, and volunteers undertook training in water sampling.
These volunteer ‘citizen scientists’ then took samples from points in Babergh rivers downstream of sewage treatment outlet pipes on coordinated dates, and these samples were returned to the central lab for processing.
Rivers that were tested included the Brett, the Box, the Glem and the Stour at different locations and with varying results.
Volunteers taking samples of river Brett water in Hadleigh
Focus on Sudbury
In 2022 the River Stour Trust put in an application with DEFRA for Bathing Status along a stretch of the Stour in Sudbury.
As we had evidence of particularly high E.coli readings long this stretch we decided to focus our resources on Sudbury while the application was underway.
Testing sites in Sudbury and Gt Cornard: 1) The Croft; 2) Mill meadows upstream; 3) Mill meadows downstream; 4) Friars ditch; 5) Friars north; 6) Landing stage; 7) Lady Island East; 8) Kings Hill outlet; 9) Cornard Lock
Volunteers tested at the same 9 spots every two weeks, and the results were sent to Polstead to be processed by Elaine in the purpose-bought incubator.
Laura Smith and Vincent McGoldrick sampling at the Landing Stage.
Citizen scientist Jess Thompson sampling at Lady Island East
Bathing status
Sudbury’s Friars Meadow was awarded official Bathing Status in May 2024, leading to 6 months of official testing by the Environment Agency every year. The results are published on the EA website.
This designation is excellent news for river users at this stretch of the river in Sudbury, who can now make a scientifically-informed choice whether to enter the water or not.
It is interesting that the designation only applied to the river along Friars Meadow, and not all the way further down towards Cornard Lock, as in the original application. Could this be anything to do with the much higher levels of E.coli that can be found down there according to our results?
Plates with high levels of E.coli bacteria growing
Results
Our results showed a high increase in E.coli after heavy rainfall, leading us to suspect that storm outfall pipes are releasing raw sewage directly into our watercourses during periods of heavy rain.
Interestingly, our results correlate with those of the Environment Agency’s official Bathing Status testing.
Bathing status sampling map
Friars Ditch
One ‘watercourse’ that shows persistently high levels of E.coli is the ditch that runs between the Valley Walk (the old railway line) and Friars Meadow.
Vincent McGoldrick sampling in Friars Ditch.
Very high E.coli readings from Friars Ditch
Graphs showing results in Friars Ditch attached above
Is this a public health hazard? Environmental health officers at Babergh have said not.
The Croft and Kings Marsh meadow
Throughout 2023 and 2024 we continued to test the Stour on the West side of Sudbury in two spots: at the Croft and at ‘Mill Meadows’ (the river at Kings Marsh just over the bridge not far from the Mill Hotel).
Again, results show high levels of E.coli particularly after heavy rain.
Citizen Scientist Steve May holds a sampling tube
Graphs showing E.coli levels at Mill Meadows and the Croft in the attached document above.
Implications
It’s undoubtedly great news that the EA is testing the river in the summer months at the Friars Meadow stretch of the Stour.
But, how many river users actually check the results?
If the E.coli levels were high enough that the Environment Agency issued a ‘Do Not Swim’ warning, how many people would see it? And how many people would take any notice?
What about the areas where people swim, but there is no Designated Bathing Status?
Young people cooling off in the water downstream of ‘Mill Meadows’ outlet
We want to see clean rivers for all, everywhere – not just in Bathing Status areas.
Going forwards
The Babergh Citizen scientists have taken a break since summer 2024. We are keeping an eye on the EA’s river testing results, and are prepared to come forward to start sampling again.
Babergh Citizen Scientists: Laura, Vincent, Polly, Jess and Elaine at Friars Meadow Landing Stage
If you want to know more about our work or about E.coli sampling, contact Laura at lsmith68@yahoo.co.uk.