I first met Ash Smith in June 2021. I emailed him to say that I was writing book about water scarcity: The Last Drop: Solving the World’s Water Crisis, which aimed to raise awareness of the issues, causes and solutions, of water scarcity and pollution. I had read about his work at Windrush Against Sewage Pollution, and would he be up for meeting me, perhaps walking the river together, to tell me more?
He generously obliged, and we met later that month near one of the jewels of the Cotswolds: Bourton-on-the-Water. Here, the River Windrush runs through the chocolate-box town under picturesque low stone footbridges and past riverside pubs, before opening up in a flourish to the delight of paddling tourists. I met Ash and his dog, Archie, an immaculately trained Labradoodle, in a rural layby, with the sun beating down and the lushness of the greenery almost iridescent.
The real Ash Smith and his dog Archie. Pic ©Tim Smedley
Ash had moved to the Cotswolds for a quiet retirement after a career in the police force. He had been a copper, but not just any copper – the type of copper who investigates bent coppers, a real-life DS Arnott from Line of Duty. But the quiet retirement didn’t last long. In 2015, he and his neighbour, Oxford Professor Peter Hammond, discovered that the local sewage works, run by Thames Water, were illegally dumping raw sewage into the river that ran through their village. Being good citizens, they reported it to the Environment Agency (EA), who duly ‘investigated’. “Although, I use that term quite loosely,” he told me. “Thames Water self-assessed that the environmental impact of them having dumped untreated sewage over many years was ‘low’. And the Environment Agency accepted that without question and took no further action.”
That really rattled Ash’s cage. Which was a mistake, because, since then, Ash and Peter founded Windrush Against Sewage Pollution (WASP) and elevated river pollution to the level of a national scandal. To such an extent that it has since been made into a televised three-part docu-drama, Dirty Business, which aired on Channel 4 in February 2026, and is now available for all on Video on Demand. Ash and Peter are played by the multi-award-winning actors David Thewlis and Jason Watkins.
Before 2015, the waste sources leading from sewage works into rivers – known as storm outflows or combined sewer overflows (CSOs) – weren’t even monitored. Since then, the EA required that, by 2023, all overflows had to be fitted with ‘event duration monitors’ to track how often and for how long they’re being used. The story broke in 2020, by when 70% of sewage outflows had monitors fitted and the data first became available. It showed that during the previous year, water companies in England and Wales had discharged raw sewage into rivers more than 200,000 times, for a combined total of more than 1.5 million hours. This was a shock to many, including me at the time, but also a massive underestimate, with 30% of outflows still unaccounted for.
By 2021, when Ash showed me the River Windrush, event duration monitors now covered over 80 per cent of the network, and the true scale of the scandal began to dawn. It was twice as bad as thought. The water companies had discharged raw sewage into rivers and coastal waters in England and Wales more than 400,000 times that year, for 3 million hours. A shocked House of Commons Environmental Audit Committee stated in its 2021–22 report: “Rivers in England are in a mess… sewage, agricultural waste, and plastic is polluting the waters of many of the country’s rivers. Water companies appear to be dumping untreated or partially treated sewage in rivers on a regular basis, often breaching the terms of permits that, on paper, only allow them to do this in exceptional circumstances.”
Exceptional circumstances were meant to mean heavy rains and storms when the combined sewage system became overwhelmed. However, exceptional circumstances were happening exceptionally often. Ash and Peter even found numerous examples of sewage works pumping raw sewage into rivers when there wasn’t any rain at all. This was happening across all the water companies.
Dirty Business tells the story of how, post David Cameron’s Austerity policies and the ‘bonfire’ of regulations, the Environment Agency began cutting down, and eventually cutting altogether, its investigations into raw sewage spills; instead, it introduced ‘operator self-monitoring’ – now the onus was on the waste water companies themselves to report if there had been an illegal spill. Unsurprisingly, few did.
Channel 4. Dirty Business, Ep.1.
Privatised water companies in England and Wales obtain, treat, and distribute drinking water and collect and treat sewage before releasing it to the environment as required by law, primarily under the Water Industry Act 1991. They are funded entirely by customer bills. On the WASP blog, Ash writes that “the well-known illegal dumping of untreated sewage… is a prolific and profitable activity and what happens in reality is very far from the short-term 'spills' that water companies claimed were only made to stop sewage backing up into homes. [Illegal spills] can, and do, go on for weeks or even months.”
Privatisation could have worked, in theory, if tempered with iron-fisted regulation. Instead, what we got was kit-gloves, even hands-free, non-regulation. If you give private business an easy way to make lots of money, they will take it – it is their statutory duty to deliver the best return for shareholders. Upgrading sewage works is expensive; dumping untreated sewage into a river or sea with impunity is cheap. It is only regulation that makes safe, treated drinking water, and clean and healthy rivers, important to water companies owned by international conglomerates.
As Hanna Swift, the EA whistleblower character in Dirty Business, says, “corporations want to make money, [and] we make sure that they don’t poison the rivers doing it”. It really is that simple. Or at least, it should have been. Self-monitoring was followed by a removal of company cars from EA inspecting staff, effectively meaning they had no way to attend incidents; and finally an order to end all onsite inspection for category 3 and 4 events (deemed ‘low impact’ but which could, according to the programme-makers, even include a 3-kilometre sewage spill) and instead “shut down these reports as unsubstantiated or to ‘silently pass’ them”.
“We [used to be able to] investigate, prosecute, whatever it took. But then they told the companies that they could regulate themselves”, says Hanna. At this point in the third and final episode, I was still nodding along; so far, so familiar to me – and, at this point, to Ash and Peter. But “that’s not all”, continues Hanna – herself a fictionalised character based on the real whistleblower Robert Forrester, who investigated inside the EA for 7 years. When EA chief Sir James Bevan warned staff against speaking out, Robert was being investigated, had been threatened with criminal sanctions and was suspended from work. “In 2021, Sir James hiked the prices the water companies paid for their permits”, continues ‘Hanna’. “It was called ‘charge funded regulation’. We get £96 million from the government. We are now pulling in £411 million from [these] charges… We’re swimming in cash”. So, newly swimming in cash from 2021 onwards, why is the sewage scandal still ongoing, and many of the same water company bosses are still in charge? I’ll look into this more – with Ash Smith’s help – in the second part of this blog.
