Much of Thames Water's supply area is classed by the Environment Agency as 'seriously water stressed', with customers in London, Swindon and Oxford particularly at risk of water restrictions during extended periods of dry weather. Building a new treatment plant that treats water from the brackish waters of the River Thames, turning into clean, fresh drinking water, will help reduce the risk of water restrictions and ensure that severe water rationing is never required. The plant will be used to convert brackish water from the River Thames into clean drinking water during times of drought or extended periods of low rainfall, or to maintain supplies in the event of an incident at other water treatment facilities. Architects Broadway Malyan designed the plan to RIBA Stage D and acted as expert witness at public enquiry.
Facts and figures
The plant produces 150 million litres of water a day which is enough to supply 400,000 households or 900,000 people and runs on 100 percent renewable energy. The plant takes water from the tidal Thames during the last three hours of the ebb tide and removes salt using a reverse osmosis process. The treated water is then transferred from Beckton to North East London in an 8 mile long pipeline which can hold 14 million litres of water and has a diameter of 1.2 metres. The plant is mainly used in times of drought or to support existing supplies if needed.
Development
The total cost of the scheme including the pipeline was £250 million. The route of the pipe was chosen to avoid residential areas and cause minimum disturbance. All construction sites were environmentally screened and all areas returned to their original condition on completion of the work.
Operation
The raw water is first treated by a conventional settlement and filtration process before the salinity is removed by reverse osmosis. Mineral salts, as found in the company's conventional water sources, are then added before final purification.
Criticism
Former London Mayor Ken Livingstone criticised the plant in 2007, calling it a "misguided and a retrograde step in UK environmental policy." Livingstone, arguing that the plant was expensive and unnecessary, said that Thames Water should instead focus on reducing waste caused by leakage and that people should be encouraged "to use less water, not more."
