31 Jan 2025
Thames Water have failed to apologise for pumping raw sewage into the River Ver for weeks.
According to water analysis website Top of the Poops, the Markyate wastewater treatment works has been releasing sewage continuously for more than 1,000 hours since December 12.
The Ver is one of the world’s rare chalk streams, of which only 220 exist, with habitats supporting a very special ecology.
John Pritchard, chair of the Ver Valley Society, said: “Markyate has the unenviable record of being the worst Thames Water sewage works in Hertfordshire in 2024, when it discharged over 4,100 hours of sewage into the River Ver. So far, we haven’t had a minute in 2025 when it hasn’t been discharging raw sewage, either.
“The Ver Valley Society calls on Thames Water to put in motion their regularly touted ‘…clear and deliverable plans to upgrade 250 of our sites..’ and bring Markyate to the top of the list.
“We understand that surveys need to be done in the first instance, when the groundwater is at a particular height, but Thames Water has already missed several opportunities to get started.
“Until these surveys are completed, solutions like sewer lining to prevent groundwater overwhelming the works, are unlikely to be seen.
“It’s all deeply frustrating as the problem at the works is well known to Thames Water, with the Ver also receiving 2,642 hours of sewage in 2021.
“Our volunteers have been regularly monitoring the water quality in the headwaters of the Ver below the sewage works. The citizen science results consistently show that the river is of ‘poor ecological status’ – for example, our latest January results reveal phosphate levels at ten times ‘Acceptable Limits’.
“The Society has been campaigning for better flow in the River Ver for nearly 50 years – and when we finally have the river flowing healthily, the sewage discharges are a real kick in the teeth.
“The better flow has seen otters on the river, water voles thriving and rare stonefly insects reappearing too. If the sewage discharges continue, all this could be put at risk. What’s more, local people will naturally be concerned about the public health implications.”
Harpenden MP Victoria Collins (pictured below with party leader Ed Davey) added: “These latest reports that Thames Water have dumped sewage into the River Ver for the past six weeks, equating to over 1,000 hours, are truly shameful – even if sadly not surprising. I have written to Thames Water to demand another meeting on the issue.
“What this shows is that now more than ever, we need strong action against Thames Water to finally end this destructive practice polluting our precious waterways.
“The River Ver is a pride of our local area – one of only 200 chalk streams globally, which enriches our natural environment, biodiversity, and provides a fantastic habitat for wildlife. It’s a beautiful aspect of our landscape – perfect for a riverside walk or paddle in the summer.
“Since my election I’ve continued campaigning to protect the River Ver and our other local waterways, including through holding my own parliamentary debate calling for ambitious action to stop sewage dumping into chalk streams, meeting with Thames Water and demanding action from the Environment Agency.
“What’s clear from this latest incident is that current controls aren’t working – the Conservatives entirely neglected this environmental crisis, allowing this horrendous pollution to continue. And Thames Water themselves have already been fined, yet they’re continuing to dump sewage at an even worse scale than last year.
“That’s why my Liberal Democrat colleagues and I are calling for strong, urgent action to stop this scandal once and for all.
Ofwat must be replaced by a tougher regulator, and water executives must lose their bonuses whilst this polluting continues.
“The Government must do this urgently, before our valuable and rare waterways like the River Ver are damaged further.”
In April 2024 Thames Water poured 850 hours of sewage into the Ver, with Flamstead Parish Council reporting a coating of brown sludge, resulting in the removal of grazing horses and the disappearance of wild birds.
In a statement the council said: “There is an aroma of effluent pervading parts of the village which is unacceptable.
“There are 220 chalk streams in the world, 85% of those are in England – so they are a very special and rare habitat.
“That habitat is really under threat and Thames Water are doing nothing to preserve it, in fact they are intent on destroying it at the moment as there is nothing being done to mitigate their policy of opening the flood gates to let raw sewage circumnavigate the treatment works as they claim to have no alternative.”
Rather than apologising for the latest crisis, a Thames Water spokesperson blamed the weather: “While all storm discharges are unacceptable, the sewage system was historically designed to work in this way, to prevent sewage backing up into people’s homes. Our region experienced one of the wettest years in 2024, resulting in exceptionally high groundwater levels in the area. This has overwhelmed our sewer system which can lead to discharges into rivers.
“We have clear and deliverable plans to upgrade 250 of our sites across the region, including at our site in Markyate, to increase treatment capacity and reduce the number of storm discharges.
“We know how much people enjoy and appreciate rivers, and we are committed to seeing waterways thrive, but we can’t do it alone. Farming, industry, road runoff, wildlife and increasingly extreme weather also play a role in river health. As infrastructure ages and demand on it increases, more investment is needed across the entire sector. That’s why we asked for increased investment in the next regulatory cycle between 2025-2030.
“We’ve put transparency at the heart of what we do, and we were the first water company to publish a real time data map on our website, which in its first year has been viewed over 350,000 times.”
