The project will involve the construction of London's deepest ever tunnel-- the Thames Tunnel -- up to 80 metres beneath ground level, and spanning32 kilometres beneath the River Thames from Hammersmith in West London, toBeckton, in East London. An additional tunnel -- the Lee Tunnel (7kilometres) -- will run from Abbey Mills in Stratford to Beckton. Thetunnels will capture and transfer sewer discharges for treatment, whichwould otherwise enter the River Thames and its tributaries during heavyrainfall.

London has a combined sewerage system, built during the Victorian era tocarry both rainfall and sewage. Overflow points were constructed along theriver banks as part of the system to prevent flooding during heavy rainfallby 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 investmentproject by far. These exceptional tunnels will have enough capacity tostore millions of litres of diluted sewage and transfer it to our Becktonsewage treatment works. This scheme is essential if we are to improve thequality of the river and reduce the environmental impact of sewageoverflows.

"To successfully implement this massive and challenging engineering projectwe need the full support of our stakeholders and a world-class team withthe appropriate knowledge and experience to take it from planning toconstruction. We are delighted to have CH2M HILL on board to help usdeliver a sewer system fit for the 21st Century and beyond."

Both tunnels will be more than seven metres wide, running beneath a vastnetwork of existing tunnels, including six Tube lines and utilities. Theoverall programme includes constructing numerous collection and diversionfacilities, a large high-head underground pumping station, and a majorupgrade 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 thisland-mark engineering programme. Together we will help the city meetcurrent and future wastewater requirements, and leave a lasting legacy thatwill improve the quality of the Rivers Thames and Lee for futuregenerations."

The Thames Tideway Tunnel scheme was approved by the UK Government in March2007. Construction of the Lee Tunnel -- which will capture half of allThames' Tideway discharges from a single overflow point at Abbey Millspumping station -- is expected to start in 2009, once the relevantregulatory and planning approvals have been obtained. The tunnel is due forcompletion by 2014. Construction of the Thames Tunnel, which will preventdischarges from 35 overflow points along the Thames Tideway, is notexpected to start until 2012 with completion in 2020.

As programme manager, CH2M HILL will help Thames Water to implement theTideway Tunnel Programme through all phases, including planning consents,preliminary and final design, construction oversight, stakeholdercommunication, commissioning and start-up of new facilities. CH2M HILL hasbeen working in United Kingdom for more than 17 years and has 255professionals in seven offices throughout UK.

CH2M HILL has managed similar projects in Singapore, where the firmprovided programme management for one of the world's largest wastewaterreclamation projects, and in Milwaukee, Wisconsin, for the first successfulcity-wide deep-tunnel combined sewer overflow system implemented in theU.S. The Milwaukee tunnel system has reduced combined sewer overflow eventsfrom more than 60 per year to an average of two per year, greatly enhancingthe water quality in Lake Michigan.

Subcontractors on the CH2M HILL team include Halcrow and TunnellingLimited.

Thames Water Utilities Limited Overview:

With over 4000 employees Thames Water is the UK's largest water andwastewater services company serving more than 13 million people in greaterLondon and southeastern England.

CH2M HILL Corporate Overview:

Headquartered in Englewood, Colorado, employee-owned CH2M HILL is anindustry-leading programme management, construction management and designfirm, as ranked by Engineering News-Record (2007). With more than$5 billion in revenue and 24,000 employees, the firm's work is concentratedin the areas of energy, water, transportation, environment, nuclear andindustrial facilities. The firm has long been recognised as a most-admiredcompany and leading employer, including being named by FORTUNE as one ofthe 100 Best Companies to Work For and one of America's Most AdmiredCompany (2008). Visit www.ch2mhill.com.

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