Ground was broken today on the Lee Tunnel, a new 6.4km sewer the width of three double decker buses, which will prevent 16M.t of sewage overflowing into the River Lee each year.
The £635M tunnel will take discharges from London’s largest combined sewer overflow at Abbey Mills in Stratford, east London, for treatment at Beckton sewage works, which is being expanded so it can deal with the additional flows.
The Lee Tunnel will help prevent 40% of the 39M.ton average of sewage which enters the River Thames and River Lee each year from 57 combined sewer overflow points.
Construction started today on one of four shafts, which will be up to 75m deep. Tunnelling work will start in 2012, with the project due for completion in 2014.
The Lee Tunnel will be the deepest tunnel ever constructed in London, and is Thames Water’s biggest engineering project to date.
Thames Water chief executive officer Martin Baggs, who cut the first sod at the Beckton shaft site, said: “Abbey Mills is the largest sewer overflow in London so the Lee Tunnel will deal with this first so we can have the biggest impact, most quickly.”
Work has already started on phase one of Thames Water’s London Tideway Improvements programme to clean up the Thames − a £675M scheme to modernise London’s five major sewage works so they can treat more waste to prevent the sites being overloaded, and treat it to a higher standard.
Phase two is the Lee Tunnel, and the final and most challenging piece of the overall plan is the proposed Thames Tunnel, which will run up to 32km from west to east London to tackle the 34 most polluting overflows along the River Thames.
Thames Estuary Partnership executive director Jill Goddard said: “The Lee Tunnel ground breaking is great to see as the start of this incredible engineering project. I am very pleased to welcome Martin Baggs, Thames Water’s CEO, to speak at the Thames Estuary Partnership Annual Forum about the proposed routes of the Thames Tunnel as part of the current consultation phase.”
Three of the country’s leading civil engineering contractors - Morgan Sindall, VINCI Construction Grands Projets and Bachy Soletanche (MVB) are working together to deliver the Lee Tunnel.