If you desire to comprehend how Britain became entangled in an ongoing sewage crisis, one that it may never fully overcome, the best starting point is not the present year, or even the year when England’s water industry was privatized in 1989, but rather over 150 years ago. It may seem peculiar to begin with a historical event from 1856, but that was the pivotal year that set the foundation for Britain’s (and much of the world’s) urban water systems. This decision has led to the current predicament of repeated sewage overflows into rivers and the lack of progress in resolving the issue.
The complexity of the modern water industry, including company financing, regulatory structures, and water processing, is overshadowed by a surprisingly simple truth. The root of the problem lies in the pipes and what flows through them. In major cities like London or Glasgow, when toilets are flushed or sinks and washing machines are used, the water and wastewater all flow into the same sewer system. Moreover, rainwater from roofs, pavements, and roads also enters the drains and sewers. This intermingling of rainwater and sewage is referred to as a “combined sewage system.”
The main issue with a combined system is its vulnerability to combined sewage overflows whenever it rains heavily. The sewage system and its pipes become overwhelmed by the rain, resulting in spills into rivers or the sea. These spills were intended to occur infrequently, only during extreme rainfall events. However, it is crucial to understand that these spills are not a flaw in the system; they are an inherent part of it.
Unfortunately, with a combined system, it is practically impossible to prevent 100% of sewage spills unless the country is covered in sewage plants or enormous tunnels and storage tanks are constructed. Alternatively, sewage could be allowed to flow back into people’s homes. This is the inherent logic of the current pipe system.
If Britain were designing its sewage system from scratch today, it would not choose the current design. It would likely opt for a separate system, with one pipe designated for sewage and another for rainwater. However, for most urban areas in Britain, it is too late to make this change. Combined systems, which perpetuate sewage spills, are deeply ingrained in these areas. Although some argue that all new sewage systems since the 1960s have followed the “separate” standard, the reality is far from clear-cut.
In an alternate reality, Britain might have never adopted the combined system, and sewage overflows would have remained a fantasy. This takes us back to the pivotal decision of 1856, made in response to the infamous “Great Stink” in Victorian London. The city had been grappling with a worsening sewage problem, leading to repeated cholera outbreaks and public health crises. Social reformers, like Sir Edwin Chadwick, advocated for change and a separate sewage system. However, the authorities ultimately chose a different design proposed by Sir Joseph Bazalgette.
Bazalgette’s solution to the Great Stink was the combined sewage system that London still relies on today. All home pipes and drains, carrying sewage and rainwater, would empty into sewers running along the Thames embankment before being discharged into the river. This system was then adopted by other towns and cities across Britain, as well as many regions in Europe and North America. Bazalgette’s decision forever altered the world.
While Bazalgette’s sewers and public works were remarkable achievements that prevented future cholera outbreaks and saved countless lives, they were designed as a combined system. As the population grew and cities expanded, with more concrete and asphalt surfaces directing rainwater into drains, sewage discharges became more frequent. In Bazalgette’s time, London’s system was only intended to discharge for around 12 days a year during heavy rainstorms. Today, there are over 60 discharge days per year.
Therefore, the fundamental issue with Britain’s sewage system lies in its design. We made the wrong choice.