Why EastEnders could be drinking sea water

The East End of London has been earmarked as the site for Britain's first desalination plant.

The plants - more common in hot, dry areas such as the Middle East, California and Mediterranean Europe - filter out the salt through a series of ultra-fine membranes. The result is suitable for drinking, showering and bathing.

Thames Water says it needs one because of a growing population and longer, hotter summers.

It is ready to seek planning permission to build a £200million facility in the borough of Newham, and hopes to start work by Christmas.

The company says London has less rainfall per head than Madrid or Istanbul, and more than half its rain is already used for the public supply.

Spokesman Andrew Boyd said: 'By 2016 London is expected to have another 800,000 people, equivalent to the population of Leeds moving here.'

Thames Water hopes its desalination plant will be fully operational by 2007, producing up to 150million litres of water a day - enough for 900,000 customers.

Unlike most such plants, which take water directly from the sea, it would convert water from the Thames estuary, which is significantly less salty than sea water.

Once the water flowed into the plant, it would be treated with reverse osmosis technology - commonly used in Mediterranean-countries - to purify it of sodium and chloride ions.

This involves applying pressure to force the trapped water through an extremely fine membrane with millions of microscopic holes to filter out the salt.

The process would be repeated four times before the treated water was pumped to an existing underground storage reservoir in Woodford, Essex, to be supplied to homes in North-East London.

Other water companies, including South East Water, are thought to be considering desalination plants as a cheaper alternative to buying land and building reservoirs.

But the proposals could face protests from environmental activists who say desalination plants can harm marine habitats.