The results so far
The River Dee at Sandy Lane has been designated as a bathing water. This doesn’t mean that the Dee is automatically safe for swimming, but it does mean that the Environment Agency is now regularly testing the water for two types of bacteria – E. coli and intestinal enterococci. These bacteria are used as indicators of faecal pollution and the potential health risk to people swimming in the river.
Sampling takes place throughout the bathing season, from mid-May to the end of September, with between 10 and 20 samples taken during this period. The first 12 samples taken on the Dee show just how much the river’s water quality can vary.
At times, bacterial levels have been relatively low and well within excellent bathing water standards. On 26 May, for example, both E. coli and intestinal enterococci were recorded at fewer than 10 organisms per 100ml.
But there have also been significant spikes. E. coli reached 560 on 10 June, 800 on 22 July and, most strikingly, 2,200 on 5 August. Intestinal enterococci also reached its highest recorded level on 5 August, at 420 per 100ml.
That means the concentration of E. coli recorded at Sandy Lane has varied by more than 200-fold. Bathing water classifications aren’t based on individual samples but on a statistical assessment of the results. Although sampling for this season isn’t yet complete, the results so far indicate that Sandy Lane is likely to be classified as Poor if the current pattern continues.
There has been little significant rainfall since mid-June, but flows in the Dee at Chester are stable as they are supported by releases from reservoirs in the upper catchment. This means the large variations cannot simply be explained by heavy rainfall washing pollution into the river, or falling river levels concentrating it. For example, E. coli increased from just 73 per 100ml on 29 July to 2,200 on 5 August, despite both samples being collected during similar conditions. There is also no obvious correlation between the high bacterial readings and the tidal cycle.
Unfortunately, the bathing water samples alone do not allow us to determine the exact cause of these spikes. Potential sources include misconnected drains, sewage discharges and livestock, all of which can introduce harmful bacteria into the river at various points across the large upstream catchment above Chester.
Recive up to date infomation here: https://environment.data.gov.uk/bwq/profiles/profile.html?site=ukd6300-40752
Finding and tackling pollution across the Dee
The Dee Trust is an independent charity with the objective of creating a River Dee free of pollution and full of wildlife. Achieving that means tackling pollution from all its different sources. Our focus is on identifying problems and then delivering targeted action to solve them.
To tackle pollution effectively, we first need to know where it is coming from. To find these sources, we train citizen scientists to monitor water quality across the Dee catchment, including the smaller streams and tributaries that feed the main river. By testing at different locations and working progressively upstream, we can help narrow down where previously hidden sources of pollution are entering the river.
Once a problem is identified, we can work with farmers, businesses, communities, water companies and other organisations to find a solution.
Our Water Wise Farming programme focuses on improving farmyard drainage, separating clean and dirty water, and improving soil health. Meanwhile, our It Shouldn’t Be in the Dee programme focuses on installing sustainable drainage systems in urban areas to capture rainfall, reduce runoff and ease pressure on sewers during wet weather, alongside mass litter picks to tackle plastic pollution.
Together, this work will help improve the long-term health of the River Dee and make it a better environment for both wildlife and the people who enjoy it.
If you would like to follow our progress, visit our website at Deetrust.co.uk or follow us on Instagram, Linkedin Facebook or TikTok.
Written by Peter Powell, CEO of the Dee Trust.