Desalination comes to the capital

Mainland UK’s first major desalination plant was opened on 7 June to provide London with a supply to use in the event of a drought.

The long-awaited Thames Gateway Water Treatment Works, at Beckton in east London, will, when required, turn brackish water from the River Thames into high-quality drinking water for over one million Londoners.

The capital is classed by the Environment Agency (EA) as “seriously water-stressed”, which means that demand could outpace supply in a long dry period. With climate change threatening hotter, drier summers and an additional 700,000 people forecast to move to London by 2021, Thames says that the new water works will be available to help provide the capital’s supplies for the future – whatever the weather.

Martin Baggs, Thames Water’s chief executive, said: “Our existing resources – from non-tidal rivers and groundwater – simply aren’t enough to match predicted demand in London. That’s why we’re tapping into the new and limitless resource of the tidal Thames, fed by the rolling oceans beyond, so we can ensure our 8.5M customers have enough water in future in the event of a drought.

“This new works is a major advance in desalination technology and in UK water resource management. Running it on biodiesel, derived from materials including used cooking oil, will also help us tread as lightly as possible on the environment, on which our core business depends.”

The plant underwent a protracted planning case and was opposed by the then London mayor Ken Livingstone on the grounds of high energy consumption.

The EA’s head of water, Ian Barker, said: “Although the Beckton desalination plant will help to provide London with secure water supplies during times of drought and peak demand, we all must do more to reduce water consumption. The Environment Agency believes that metering should be rolled out to households in water-stressed areas. The water industry must also continue to manage leakage from its network of pipes.”

David Bland, chairman of the Consumer Council for Water’s London & South East region, said that he welcomed the opening, “notwithstanding the obvious cost of building and running the plant”.

He added: “The security of the water supply for all users – in all circumstances – is our absolute overriding priority, and this plant will contribute significantly to that assurance at times of the greatest risk to supplies.”

The new works is able to produce 150Mld when needed, enough to supply 400,000 homes. Thames says its water will be blended with other supplies, so up to 580,000 properties in north-east London (1.4M people) will potentially receive it in varying proportions. And because London’s water supply is connected by a Ring Main, the benefits will be felt across London.

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