Program manager appointed

Thames Water has appointed CH2M HILL as program manager for the Thames Tideway Tunnel scheme — to help deliver a ‘super-sewer’ that will prevent overflows from London’s sewers entering the River Thames.

The project will involve the construction of the Thames Tunnel that will be up to 80 m beneath ground level, and span 32 km beneath the River Thames from Hammersmith in West London to Beckton in East London.

An additional tunnel, the Lee Tunnel (7 km), will run from Abbey Mills in Stratford to Beckton.

The tunnels will capture and transfer sewer discharges for treatment, which would otherwise enter the River Thames and its tributaries during heavy rainfall.

London has a combined sewerage system, built during the Victorian era to carry both rainfall and sewage. Overflow points were constructed along the river banks as part of the system to prevent flooding during heavy rainfall by directing sewage into the River Thames and its tributaries.

Both tunnels will be more than 7 m wide, running beneath a vast network of existing tunnels, including six Tube lines and utilities. The overall program includes constructing numerous collection and diversion facilities, a large high-head underground pumping station and a major upgrade at the Beckton sewage treatment works.

As program manager, CH2M HILL will help Thames Water to implement the Tideway Tunnel Programme through all phases, including planning consents, preliminary and final design, construction oversight, stakeholder communication, commissioning and start-up of new facilities.

Construction of the Lee Tunnel — which will capture half of all Thames’ Tideway discharges from a single overflow point at Abbey Mills pumping station — is expected to start in 2009, once the relevant regulatory and planning approvals have been obtained. The tunnel is due for completion by 2014. Construction of the Thames Tunnel, which will prevent discharges from 35 overflow points along the Thames Tideway, is not expected to start until 2012 with completion in 2020.