Thames Water is investing £70 million over the next three years to upgrade the Northern Outfall Sewer and ensure its pipes are resilient for future generations.

The sewer, which serves over 4 million people, runs from Wick Lane to Beckton Sewage treatment works, the largest in Europe.

The Victorian pipes were originally constructed between 1860 – 1865 and each sewer is 2.7metres in diameter – large enough to drive a transit van through. Wastewater flows through the pipes at a rate of up to 20,000 litres per second.

Work will be carried out at three key locations during the upgrades starting from March 2023.

The company will use pipes made of glass reinforced plastic as part of the upgrade which will help provide reliable services over the next 100 years and as the population of the capital increases.

Richard Smith, Thames Water project manager, said:

“The Victorians built thousands of miles of sewer pipes across London including the Northern Outfall Sewer.

“As custodians of this incredible infrastructure we need to ensure our pipes are resilient to the pressures of climate change and population growth and we can continue to provide reliable services to our customers. This upgrade to our network will help protect customers and the health of the River Thames.

“The Northern Outfall Sewer supplies Europe’s largest sewage works at Beckton, which treats the waste of more than four million Londoners, so we need to make sure the pipes continue providing this vital service for at least another 100 years.”

Beckton Sewage Works forms a key part of London’s £4billion new super-sewer, the Thames Tideway Tunnel. When it opens in 2025, the 15-mile-long tunnel will capture all of the ‘first flush’ from the big London sewers after heavy rain and reduce discharges by around 95% in a typical year to the tidal River Thames.