Sewage pollution

Combined Sewage Overflows (CSOs) are pipes in our water system that combine both rainwater and sewage, and connect directly to our rivers. They were designed as emergency infrastructure to prevent sewage backup during extreme rainfall events. Legally, water companies are currently allowed to release untreated sewage through these pipes (CSOs) during ‘exceptional circumstances’.

However, the water industry takes advantage of CSOs to add capacity to their network, rather than spending money on updating the outdated infrastructure. They discharge raw sewage straight into our rivers and seas, even when there is no rain. In 2023, 3.6 million hours of raw sewage was dumped into our rivers, a 69% increase on the previous year. This must stop.

Worst of all, even treated sewage pollutes our rivers. Treated sewage (effluent) in the UK still often contains an abundance of dangerous contaminants and pollutants—high levels of fecal matter, bacteria, viruses, chemicals, and microplastics. The treatment process falls short of safe standards, but is permitted by inadequate regulations that fail to ensure the removal of these harmful substances to a sufficiently high level to protect the environment and the public. This applies unless the waterway has bathing water status (fewer than 20 inland in the UK), is home to a fish farm, or serves as a place of abstraction. As a result, water companies pollute freely on a daily basis.

Presently, water companies have little incentive to change their reckless behaviour, with regulators consistently failing to enforce legislation and issue meaningful fines.

Fines for breaking the law are so infrequent and minimal that polluting becomes financially advantageous, effectively encouraging companies to continue the harmful practice.

This highlights the failure of the privatisation experiment in our water sector and the urgent need for new financial and governance structures that prioritise people and the planet over profit.

As the only country in Europe with a fully privatised water sector, England should turn to its European neighbours for evidence-based models of how water management can be successfully and sustainably implemented.

Healthwise, sewage released into our rivers contains harmful fecal bacteria and viruses, including Escherichia coli (E. coli) and Enterococci, which present significant health risks to humans. Even minor exposure through a blister or cut can lead to gastrointestinal and skin infections. In more severe cases, these infections can escalate to conditions like sepsis, which can be life-threatening. Thousands of reports of infections and illnesses are documented annually from individuals engaging in water-based activities in contaminated rivers. However, the actual number of cases is likely much higher, as many incidents go unreported.

Economically, the costs to rectify these issues are staggering—between £350-600 billion to overhaul the sewage system and prevent further ecological degradation. These costs, if passed on to consumers, could exacerbate the cost of living crisis, highlighting the urgent need for the water industry to shoulder the burden of infrastructure reform.

Sewage pollution also severely impacts peoples livelihoods and small businesses across the country, who rely upon the resources and recreation provided by clean healthy rivers.

Ecologically, whether treated or untreated, sewage alters and degrades critical ecosystem processes via loss of critical species. Evidence clearly shows a decline in water quality where sewage is discharged, and with it a reduced invertebrate and fish abundance and overall species richness.

This is a result of the influx of nutrients from sewage, which fosters algal blooms, depleting oxygen levels and consequently devastate river biodiversity and wildlife. Additionally, sewage pollution impacts the breeding and feeding patterns of various species, leading to population decline and potentially catastrophic impacts on whole ecosystems.

Pictured: Sewage entering waterbody

Every river is local. Empowering local communities is crucial in addressing the UK’s sewage pollution crisis because it mobilises public pressure, enhances accountability, and drives local solutions. By gathering robust data, engaging local politicians and authorities, reporting spills & breaches, local communities give their river a voice in the fight against filth. It is imperative that those on the front line, witnessing the decline of their rivers first hand, are included in decision making.

The water industry continues to treat our rivers and waterways like an open sewer. The currently spineless regulators must enforce stricter CSO discharge permits and impose higher financial penalties on water companies for failing to meet agreed targets.

These regulators must be reformed and given back their funding so that they can enforce much needed severe penalties, shorten prosecution time, and increase convictions.

Years of budget cuts and political neglect have severely weakened the ability of regulators to protect our waterways. The Environment Agency (EA), Natural Resources Wales, and OFWAT lack the resources to enforce environmental laws, conduct robust water quality monitoring, and hold water companies accountable. Without proper funding, polluters continue to operate with impunity. To restore credibility and effectiveness, these agencies must be equipped with adequate staffing, up-to-date monitoring technology, and the legal authority to impose severe penalties—ensuring that water companies can no longer treat fines as a mere cost of doing business.

Despite the expansion of Event Duration Monitoring (EDM), real-time surveillance of sewage discharges remains inadequate. Current systems track when and how much sewage is discharged, but not its impact on water quality. To hold water companies accountable, we need a stronger, more transparent framework—one that integrates real-time water quality monitoring, mandates detailed pollutant reporting, and ensures public access to this data. Without this, companies can continue polluting while hiding behind incomplete and misleading metrics.

Pictured: Sewage overflow actively discharging

Pictured: Brown sewage in the sea