A £123million project to upgrade the Beckton sewage works so it can cope with London’s growing population is due to start early next year.

International engineering firm Laing O’Rourke will build a completely new inlet works and extend aeration lanes and settlement tanks in the three-year upgrade, after being awarded the contract by Thames Water.

Beckton Sewage Treatment Works, which is the largest in Europe, will also be prepared to receive wastewater from the new Thames Tideway Tunnel, a 25km “super sewer” under the river due to be completed by 2024.

Thames Water’s capital delivery director, John Bentley, said: “By ensuring we can take the flow from the ‘super sewer’, this project will help to improve the quality of the River Thames, as well as making sure the site is ready to handle the expected increase in London’s population in the future.”

The first works at Beckton was built in 1864 by Sir Joseph Bazalgette as part of the revolutionary Victorian sewer network, which drastically improved water quality in the Thames.

It now treats the wastewater of almost 4 million people.

The Beckton works has received major investment in the last 15 years and now produces half of its energy needs onsite. Laing O’Rourke’s UK head of infrastructure, Declan McGeeney, said: “Six years ago, we delivered a substantial upgrade to Beckton and we’re delighted Thames Water has trusted us to return.

“The project will maximise the use of digital engineering and off-site manufacture, with every detail of the works being built virtually before the real thing.

“Many of the tanks, such as the walls of the new activated sludge plant, will be built at our factory in Nottinghamshire before being transported for assembly on site.

“These modern methods of construction help us to deliver six months faster than traditional methods would allow.”

The upgrade project, which is expected to create about 30 jobs for local workers, is part of a 25-year investment plan to ensure the site meets the best environmental standard.

Thames Water is one of a number of utilities companies working with the Mayor of London on an infrastructure package to help kickstart the economic recovery from the Covid-19 crisis.