THAMES WATER has embarked on a pilot scheme that could result in a sigificant number London's water mains being replaced or relined over the next 20 years.
For the pilot six areas have been identified where accurate information is available about the amount of leakage, and where rates are particularly high. They include parts of Camden, Kensington & Chelsea, Tower Hamlets and Hackney. Within each area all the mains are either being replaced altogether or relined with structural polyethylene liner.
The first contract, worth £5M, began in July and is due for completion at the end of November. Contractor J Murphy is replacing or relining 21km of mains pipes in the Bethnal Green area of east London, where there are 6,500 properties and 1,500 connections to the network.
Contracts have been awarded to Thames' framework contractors Murphy and Clancy Docwra for the next five schemes, with costs ranging from £2M to £5.5M.
Two are scheduled to start before Christmas and three in the New Year.
Each area is one of Thames Water's 330 'District Metering Areas', and the company intends - eventually - to replace selected DMA's over the coming years.
Thames Water programme manager Dave Allen says the water regulator Ofwat has proved supportive of the principle so far, but longer term funding will depend on the success of the pilots.
London's water mains are among the oldest in the UK - many are over 100 years old - and are particularly susceptible to leakage because of heavy traffic loads, historical bomb damage and the effects of heave in the surrounding clay. The rate of leakage from the city's water mains is above the national average, and Thames believes wholesale replacement or relining is one of the best ways to reduce this in selected areas.