Thames Water, the biggest water provider in the UK – covering most of Greater London, Luton, the Thames Valley, Surrey, Gloucestershire, north Wiltshire, far west Kent, and some other parts of England – has allegedly illegally dumped untreated sewage in rivers on two out of every three days for the past three years, according to new data. First reported in the Financial Times, the spills are said to have been inaccurately recorded and pose a serious public health risk.
Where have the spills been?
Thame’s Water’s sewage treatment facilities in West Oxfordshire and the Cotswolds reportedly dumped sewage illegally on 735 days between 2018 and 2020, according to data collected by the Windrush Against Sewage Pollution Campaign Group.
There is a live map from the Rivers Trust – here – which shows sewage dumps and overflows across the UK, so you can check your area there.
You can also sign up for dumping notifications from Thames Water here, and follow this Twitter page which posts updates about spills and dumps.
The Environment Agency (EA) runs a water quality check page too – you can find it here.
READ MORE: Pollution is the biggest threat to wildlife on our British rivers
What are the rules for sewage dumping?
The EA allows water companies to discharge some untreated sewage into rivers via storm overflows when rainfall runoff from roads and roofs overloads sewage works.
This is partly to avoid sewage backing up into homes, gardens and streets.
However, companies are prohibited from making “dry spills” of untreated sewage when there is no rainfall or “early” spills of sewage discharged when a works fails to maintain a minimum rate of treatment.
On Thames Water’s ‘river health’ page, it states: “Putting untreated sewage into rivers is unacceptable to us, to our customers and to the environment.
“But after heavy rain it is sometimes necessary, and permitted, as a last resort to prevent it from flooding homes, gardens, streets, and open spaces.
“We’re working hard to make these discharges unnecessary, with the help of the government, Ofwat and the Environment Agency.”
Thames Water said it “could take up to four days” for sewage to clear the water after a dump.
The EA said on its official ‘swim healthy’ page: “The Environment Agency monitors over 400 designated bathing waters in England between May and September, and each is given an annual classification of Excellent, Good, Sufficient or Poor.
“As well as the annual classification, the Environment Agency makes daily pollution risk forecasts for a number of bathing waters where water quality may be temporarily reduced due to factors such as heavy rainfall.”
But Professor Peter Hammond, a former professor of computational biology at University College London, who carried out the research, said the revelations demonstrated the inadequacy of the EA’s detection of illegal spills.
He said: “Furthermore, it suggests the annual Environment Performance Assessment of sewerage operators, a key element of the financial regulation of the water industry by Ofwat and the EA, is based on incomplete data and is like a house built on sand.”
In response to this story, an Environment Agency spokesperson said: “The EA takes our responsibility to protect the environment very seriously. The regulations are clear and are enforced robustly. Water companies know they have a duty to avoid pollution, and that they must act quickly to address failures and reduce damage if it occurs or face enforcement action.
“We are currently reviewing data from over 12,000 storm overflows to identify those which may be operating in dry weather or are potentially non-compliant with permit requirements – this will filter out storm overflows which are of concern so we can request further information from the water companies to assist with our investigations.”
And a Thames Water spokesperson said: “We’ve received the report and will be looking at it carefully in the coming days. We regard all discharges of untreated sewage as unacceptable and will work with the government, Ofwat and the Environment Agency to accelerate work to stop them being necessary. Our planned investment in our sewer network and the upgrading of sewage treatment works across our region, including Oxford and Mogden, will help improve the situation.
“Our aim will always be to try and do the right thing for our rivers and for the communities who love and value them. We have a long way to go – and we certainly can’t do it on our own – but the ambition is clear.”