7th October 2024 Environment Testing Results

Here are the results from our recent Monday 7th October "sampling safari” with commentary and a few bits of news from the work we have all been doing over the past month.

Every blue dot indicates an e.Coli colony. 9 dots in each round disk is the maximum DEFRA allows for safe bathing.

The most recent sampling included a couple of new locations, notably on the Earl Soham branch towards the Anglian Water sewage works and an additional one in the Lark/Fynn sector. This was also the first time we have used the new COM-300 test meter to measure temperature, pH, electrical conductivity and dissolved solids and the turbidity tube to measure turbidity in key locations. These data add to our growing stock of environmental monitoring information about our river system which now covers observations about vegetation, river state and the like. There is too much to share here but we are going to be creating a database and mapping tool to bring all these features together.

The highlights from this sampling round are:-

E.coli - in line with previous months, E.coli levels are broadly similar although the levels at Debenham, Easton and Rendlesham STWs have dropped away considerably. The Lark and Fynn sector shows some falls but a spike at Tuddenham downstream from the small STW there.

The biggest rise and concern was the level of E.coli contamination found in the tidal section from Melton all the way down to Waldringfield. After months of low E.coli - within the “safe bathing limit” - at these locations, we have seen a significant spike with very high E.coli levels recorded at Woodbridge Tide Mill (over 250 colonies for 1ml) and at Waldringfield (109 colonies per 1ml). These levels are 12 to 20 times over the safe bathing designation for Waldringfield (which only applies between 1st May and 30th September). This pollution incident was reported to the Environment Agency last week (NIRS 02313710). We have contacted the Environment Agency and Anglian Water for them to follow up. Thus far, it seems that none of the nearby Anglian Water STWs have reported a spill or storm overflow.

We are awaiting the results of the EA investigations and will let you know the outcome when we have more to tell. 

There are three maps below which show the Deben and Debenham locations and E.coli levels plus one which is Woodbridge area specific. We are also including a photo of the E.coli plates so you can see the scale of the pollution.

Phosphate - the phosphate levels along the river were similar to those in September although those for Debenham, Easton and Rendlesham are lower than in previous months. There is also some evidence that levels at Charsfield STW are falling. Our hope is that the installation of phosphate stripping technology is starting to have a real impact in reducing phosphate pollution. The Debenham results are almost all lower than for September, partly due to higher river flow. Interestingly, there was no evidence of any tidal section phosphate or nitrate spike similar to that for E.coli.

0.1 is the Natural England limit for a healthy river.