Mid-August 2026 River Deben Environment Monitoring Results

We conducted our first mid-month sampling and testing at selected hotspots and sites of interest across the Deben catchment last week. This is part of our move to conduct fortnightly testing at around 20 of the 70 monthly sampling locations. 

Sampling took place over several days but the results give a reasonable indication of those areas which will need more frequent monitoring over the coming months.

1. Tidal Section

We sampled at Waldringfield, Kyson Point, Deben Yacht Club and close to Ferry Quay (Houseboats by Shelter). The E.coli results showed almost no E.coli at Waldringfield but quite significant bacterial pollution at the three Woodbridge sites. All three were above the 9 CFUs per 1ml with Kyson at 24 CFU's per 1ml and Ferry Quay at 22CFUs per 1ml; so unsafe for swimming even at high tide.

There was a similar picture for phosphate at the 3 Woodbridge sites being above the healthy river threshold. Water users reported significant algal and weed growth in the area, likely to be caused by excess phosphate. Nitrate levels by contrast were low at all the sampling points.

2. River Fynn at Tuddenham/Playford

Richard Ward, our sampler at Tuddenham had previously identified several outlet pipes close to the STW there over the past months. We sampled and tested here and at Playford and have clearly identified the STW outfall pipe which showed very high levels of E.coli (650 CFU's per 1ml) and phosphate (5.0 mg/litre) emissions. The numbers for the downstream sample point were similarly high with Playford being around the trend for that site. 

The Tuddenham results are concerning given that planning applications for new housing development are being proposed nearby and the works is relatively close to capacity.

Phosphate results showed a similar spike at the Tuddenham STW pipe.

3. Ufford  

We sampled at the Ufford Hole (now much shallower due to the weir breach) and recorded very low levels of bacterial pollution (2 CFU's per 1ml) and low phosphates here too. This is encouraging given the low flow and water levels.

There were similar quite low results at the Rendlesham WATR site (where the real-time sensor is tethered) with E.coli at 12 CFU’s per 1ml and phosphate around 0.20 mg/litre; these are in line with or lower than recent trends.

4. Wickham Market to Crettingham 

We selected four sites for sampling; most close to known pollution sources. The Charsfield STW and its downstream partner have been a major hotspot with bacterial and phosphate pollution for many months.  Our data form last week confirms these high levels for E.coli - see petri plates.

Encouragingly, phosphate levels have dropped back considerably at the Charsfield STW and are now back well within the EA permit limit and also under the 1.0 mg/litre level for other larger STW's. Other phosphate numbers on the three sites are broadly similar.

The Wickham A12 sample was also high in line with previous experience. Of greater concern is the Brandeston Bridge result as this site in usually close to or within the "safe" 9 CFU's per 1 ml guideline. A count of around 90 plus CFU's per 1ml suggests serious local pollution and this needs further checking.

5. Debenham

The three sites selected here all had water (many other sites were still dry despite the rainfall earlier last week). Just below the STW outfall, E.coli levels were somewhat lower but phosphates rather higher than earlier in the month - the latter was still well within the Debenham STW EA permit level of 1.0 mg/ litre.

Check out our River Deben Water Quality Dashboard for detailed results by

location.