History of the UK's sewers
London's Sewers are a triumph of Victorian engineering
Until the middle of the 19th Century, raw sewerage used to flow directly into the river Thames, which was also used for drinking water.
As a result, London faced repeated outbreaks of cholera, with one of the worst epidemics killing over 10,000 Londoners in 1853. It was not until the following year that a scientist named John Snow proved the link between cholera and contaminated water in London, tracing multiple cases back to a single pump in Soho.
In 1858, a particularly warm summer amplified the sewage issues for all those near the Thames - including the occupants of Parliament - creating what is known as 'The Great Stink'. This, together with the frequent outbreaks of cholera, gave impetus to legislation enabling work to begin on sewers and street improvements.
The government soon passed legislation, with work beginning in 1859. By 1866, most of London was connected to a sewer network devised by Joseph Bazalgette. His system used 82 miles of intercepting sewers, as well as a further 1,100 miles of street sewers, to ensure that the foul water from old sewers and underground rivers did not contaminate the Thames and the public drinking water supply. Bazalgette achieved this by diverting wastewater along low-level sewers, built behind new embankments beside the Thames, before it was taken to newly designed treatment works.
By the end of the century, Bazalgette's sewers, combined with sustained investment in other areas of sanitation across the country, had helped to considerably reduce infant mortality and increase average life expectancy. Through sanitation projects such as Bazalgette's, public health across Victorian Britain was transformed, with countless lives saved and a more productive workforce created.
The extended sewers are still used in the present day and serve over eight million people in the city of London.