Thames Water is carrying out a £200M upgrade to increase the amount of effluent treated at Crossness Sewage Treatment Works in east London and reduce overflows into the Thames.
The improvements will enable the site to treat 44% 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 be capable of powering 1000 homes and 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.
“In heavy rainfall storm tanks provide a lower standard of treatment and overflow into the tidal stretches of the River Thames.”
Steve Shine, Thames Water
The work at Crossness is part of a £650M 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.
Thames Water chief operating officer Steve Shine said the project is a fundamental step in improving the quality of the river.
“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,” he said.
“The improvements at Crossness Sewage Works, which currently serves two million Londoners, will enable the site to fully treat 44% more sewage arriving at the site during heavy rainfall, and allow for a 6% population increase until 2021.”
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 70m high anemometer which will provide information on wind speed ahead of detailed design of the new wind turbine, planned to be installed in 2013.
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.