Thames Water is carrying out a £200million upgrade at Crossness Sewage Treatment Works in east London.

The improvements will enable the site to treat 44 per cent more sewage than it does now, significantly reducing the amount of storm sewage that overflows into the River Thames during heavy rainfall when the site becomes overloaded.

The project includes the installation of a wind turbine - the first ever to power a British sewage works - that will help generate up to half the energy needed to power the site. The upgrade will also see new odour controlled treatment processes and environmental enhancements.

The work at Crossness is part of a £650million programme to improve treatment standards and increase the volume of sewage treated at London's five major sewage treatment works - Crossness, Mogden, Beckton, Long Reach and Riverside.

Steve Shine, Thames Water's Chief Operating Officer, said:

"This work marks a fundamental step in improving the quality of London's iconic river.

"We inherited a Victorian sewerage system, which is struggling to cope with the demands of 21st century London. Since it was built, the capital's population has almost doubled, climate change is bringing less frequent but heavier rainfall and many green spaces have been concreted over, preventing natural drainage.

"Although our sewage works operate well under stable, dry weather conditions, in heavy rainfall excess flows pass through storm tanks, which provide a lower standard of treatment and overflow into the tidal stretches of the River Thames to avoid sewage backing up onto the streets or even into people's homes.

"The improvements at Crossness Sewage Works, which currently serves two million Londoners, will enable the site to fully treat 44 per cent more sewage arriving at the site during heavy rainfall, and allow for a six per cent population increase until 2021.

"The installation of a new wind turbine, which will be capable of powering 1000 homes, combined with the energy generated from processing sewage sludge, will help to power up to half of the site."

Before main construction starts in spring 2010, enhancement work will start at Crossness Nature Reserve and the Southern Marshes - including creating a suitable habitat for water voles and birds. Other work includes clearing vegetation ahead of the bird-nesting season, constructing a new temporary access road, and installing a temporary 70 metre-high anemometer which will provide information on wind speed ahead of detailed design of the new wind turbine, planned to be installed in 2013.

 Lee Tunnel work starts in April

The work at Crossness forms part of Thames Water's wider London Tideway Improvements programme. This is made up of three major schemes: the Lee Tunnel, Thames Tunnel and Sewage Treatment Works Upgrades.

In April 2010, Thames Water plans to start work on the £600million Lee Tunnel project, the first of the two tunnels, which will collectively capture in excess of 32 million tonnes of sewer overflows to the River Thames each year. The four-mile tunnel will be as much as 75 metres deep, running from east London's Abbey Mills Pumping Station to Beckton Sewage Treatment Works. The seven-metre diameter tunnel - the width of three London buses - will capture sewage mixed with rainwater that would otherwise overflow into the River Lee at Abbey Mills following heavy rain.