A decade after it was first revealed, London's "super sewer" is now finally complete. The £5 billion (US$6.3 billion) project is expected to revolutionize the handling of human waste in the British capital.
The Thames Tideway Tunnel connects to London's existing Victorian-era sewer system at 21 different points, boosting its capacity. The original 150-year-old sewer system was severely overwhelmed, having been designed to serve a maximum of four million people but required to handle over double that, resulting in human waste and stormwater runoff being regularly dumped in the Thames, a major river in the area.
The super sewer has a length of 25 km (15.5 miles). Its main tunnel is 7.2 m in diameter (23.7 ft), the equivalent of three London double decker buses, while its connection tunnels are either 5 m (16.4 ft) in diameter or 2 m (6.6 ft) in diameter. It has a capacity of 1.6 million cubic m (roughly 56.5 million cubic ft), which is a whole lot of sewage.
Construction on the project began in earnest in 2016 at 24 sites around London. Over 20 deep shafts – some as wide as the dome of St Paul's Cathedral – were constructed across the city. Six tunneling machines were used in all and were named in honor of inspirational women from the local area, including women's rights campaigners, a charitable doctor and a female scientist.
Thanks to the new system, the equivalent of 2,200 Olympic-sized swimming pools of sewage has been prevented from entering the river, to date. There's still work to do, however, and the team will be monitoring its performance during heavy rainfall.
"This is another significant step forward – with this final connection complete, the super sewer is fully up and running and protecting the Thames," says Tideway CEO Andy Mitchell said. "Our next step is to test it in storm conditions – which is why we are keeping a close eye on the weather – and we will do this over the coming months. We are at the start of a new chapter for London and its river. Our mission has always been about creating not just a tunnel, but a healthier, thriving environment for the river and its inhabitants. We look forward to seeing a real impact in the years to come and sharing everything we learn about the positive changes."
Source: Thames Tideway Tunnel
