The west section is largely through clay, entering a section of sand at its eastern end. Valued at GBP 416M, it incorporates seven separate work sites along the route.

Mobilisation work for the ‘West’ section begun in September last year with completion scheduled for 2022.

Upon completion, the Thames Tideway Tunnel will ensure the capital’s sewer system is fit to support its projected population for at least the next 100 years, and will tackle the issue of discharges of untreated sewage that currently enter the River Thames on a regular basis.

The new 25km tunnel will be the largest infrastructure project ever undertaken by the UK water industry.

Nick Roberts, UK CEO at Atkins, said: “A healthy River Thames plays an essential role in the wellbeing and prosperity of the City of London and its people. The Thames Tideway Tunnel will help transform the river and we are very pleased that BMB chose the valuable experience, expertise and approach we’ve developed with Arup from projects such as Crossrail. We look forward to playing our part in promoting a positive change in the relationship that Londoners and visitors have with the Thames.”

Alan Belfield, UKMEA Chairman, Arup said: “The Thames Tideway Tunnel is one of the UK’s most challenging, yet important, infrastructure projects. We have already made great strides in creating a cleaner and safer River Thames but there is a clear need to modernise our essential infrastructure. Partnerships such as ours with Atkins will play a pivotal role in driving forward these major feats of engineering and we look forward to working together on this unique project to see the benefits it will provide to the city.”