August 5th Water Test results on the Deben

Here are the results from our whole-river sampling survey for the River Deben catchment on 5th August.

E.coli and Phosphate results were similar to those in June and July’s in many areas although both E.coli and phosphate levels were higher in the River Fynn and Lark and at Potsford Brook, due in large part to reduced river flow.  Reduced river flow and the hot weather, combined with excess nutrients - phosphates, nitrates and ammonia -  led to much more weed growth, choking the river in places with rushes, weeds and green algal slime. 

An unusual E.coli spike at Ramsholt Quay (well above the safe bathing limit set for Waldringfield) was reported to the Environment Agency who are investigating the possible sources. Several estuary users also commented on the presence of large amounts of green slime on the banks and mudflats, probably a combination of hot weather and nutrient levels. 

Both July and August phosphate levels at and downstream from Anglian Water’s Debenham sewage treatment works were much reduced. This is in line with the commissioning of phosphate stripping technology there recently; both months show phosphate emissions with the new Environment Agency permit levels due to come into force at the end of 2024.