From tide to tap

The security of London’s future water supplies is more certain after the government confirmed it has granted planning permission for the Thames Gateway Desalination Plant in Beckton.

The announcement by the Secretaries of State for the Department for the Environment Food and Rural Affairs (DEFRA), and the Department of Communities and Local Government (DCLG), follows a legal undertaking by Thames Water agreeing not to operate the plant until it has entered into an operating agreement with the Environment Agency.

Thames Water has confirmed that the plant will only be used during times of drought or extended periods of low rainfall, or to maintain supplies in the event of an incident at its other water treatment facilities.

The plant is the first of its kind to be built in the UK and will be able to provide up to 140 million litres of drinking water a day – enough for nearly one million people – making the prospect of future water restrictions, such as hosepipe and sprinkler bans, less likely.

'The desalination plant is a vital part of our plans to secure future water supplies to the capital. With pressures such as climate change and population growth the plant is essential alongside our continuing progress in reducing leakage and proposals for a new reservoir in Oxfordshire,' said Richard Aylard, Thames Water's Director of External Affairs and Sustainability.

'Building the plant will be technically challenging. However, we have been successfully running a pilot plant to test the process and we are confident that when built the new plant will be able to supply drinking water for up to a million people. Although the technology is widely used throughout the world, it will be the first time that any UK water company has attempted it. We have also made a commitment to run it entirely on renewable energy and will be having discussions soon with potential suppliers of the bio-fuels we intend to use as our green power source,' he added.

Due to the comparatively high energy consumption of the plant, using up to twice the amount as conventional water treatment facilities of similar size, it will only be used when necessary. In some years the plant may not need to operate at all, in others it will run most of the time but the best estimate is that on average, it will run for up to 40 per cent of the time, over the next 25 years.

Construction is due to start in 2008 and the plant is expected to be completed and producing safe, clean drinking water by the second half of 2009.