LONDON, UK, March 14, 2008 -- Thames Water has appointed CH2M Hill as program manager for the Thames Tideway Tunnel scheme -- to help deliver the 'super-sewer' that will prevent overflows from London's sewers entering the River Thames.
The project will involve the construction of London's deepest ever tunnel -- the Thames Tunnel -- up to 80 meters beneath ground level, and spanning 32 kilometers beneath the River Thames from Hammersmith in West London, to Beckton, in East London. An additional tunnel -- the Lee Tunnel (7 kilometers) -- 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.
Steve Walker, Major Projects Director for Thames Water, said: "The Tideway Tunnel scheme is Thames Water's biggest single investment project by far. These exceptional tunnels will have enough capacity to store millions of liters of diluted sewage and transfer it to our Beckton sewage treatment works. This scheme is essential if we are to improve the quality of the river and reduce the environmental impact of sewage overflows.
"To successfully implement this massive and challenging engineering project we need the full support of our stakeholders and a world-class team with the appropriate knowledge and experience to take it from planning to construction. We are delighted to have CH2M Hill on board to help us deliver a sewer system fit for the 21st Century and beyond."
Both tunnels will be more than seven meters 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 Beckton sewage treatment works.
Lee McIntire, President and COO for CH2M Hill, said: "We look forward to working with the Thames Water team to deliver this land-mark engineering program. Together we will help the city meet current and future wastewater requirements, and leave a lasting legacy that will improve the quality of the Rivers Thames and Lee for future generations."
The Thames Tideway Tunnel scheme was approved by the UK Government in March 2007. 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.
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. CH2M Hill has been working in United Kingdom for more than 17 years and has 255 professionals in seven offices throughout UK.
CH2M Hill has managed similar projects in Singapore, where the firm provided program management for one of the world's largest wastewater reclamation projects, and in Milwaukee, Wisconsin, for the first successful city-wide deep-tunnel combined sewer overflow system implemented in the U.S. The Milwaukee tunnel system has reduced combined sewer overflow events from more than 60 per year to an average of two per year, greatly enhancing the water quality in Lake Michigan.
Subcontractors on the CH2M Hill team include Halcrow and Tunnelling Limited.
With over 4000 employees Thames Water is the UK's largest water and wastewater services company serving more than 13 million people in greater London and southeastern England.
Headquartered in Englewood, Colorado, employee-owned CH2M Hill is an industry-leading program management, construction management and design firm, whose work is concentrated in the areas of energy, water, transportation, environment, nuclear and industrial facilities.
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