Equivalent Population

Britain's first desalination plant with world-first technology

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The construction of the first desalination plant in London has been driven by population growth as well as the scarcity of natural resources in the area.

Because raw water is subject to wide variations in salinity, temperature and concentration of suspended particles and organic matter, depending on the tides and the time of year, numerous pretreatment methods have been tested for 18 months in a pilot plant.


This ensures that the water to be further treated in the reverse osmosis membranes is of a quality that guarantees the reliability of the entire process under these conditions of varying water quality at a reasonable cost.

Environmental Impact Management

During the construction of the Beckton (London) desalination plant, work was carried out on barges on the shore to avoid affecting the aquatic fauna, especially crustaceans and mollusks.

In addition, methods were used in the installation to prevent the impact on the surrounding aquatic fauna by means of grids, acoustic alarms and sweeping of pipes with countercurrent air. In this way, the suction pipes operate intermittently so that they only work when the tide is low, mainly to protect the fish fauna. A 200 dB underwater sound barrier is also generated to create a preferential escape path for fish.

The area around the desalination plant is now widely used by hundreds of waterfowl of numerous species foraging for food, mainly small fish, crustaceans and mollusks that were preserved by the prevention measures implemented during construction.

General Information

  • Project: Beckton Desalination Plant
  • Entity: Thames Water Utilities Limited
  • Location: London, Great Britain
  • Capacity: 150,000 m3/day  
  • Population: 900,000

Key points

  • The catchment is carried out in the Estuary of the River Thames during the hours of low tide, in order to guarantee the appropriate quality of the raw water of the process.
  • Hypochlorite dosage, polyaluminium chloride and sulphuric acid.
  • Lamellar sedimentation.
  • The plan has 17 sand filters.
  • 19 filter prelayer with earth diatom of 28 µm.
  • For safety filtration, the plant has 10 selectivity cartridge filters of 5 µm.
  • Dosage of bisulphate for the elimination of residual chlorine.
  • The reverse osmosis plant uses a unique design with 4 stages to minimise the specific energy consumption of the process, as well as the flow in the main elements at each stage.
  • Stages 1 and 2 are configured with 9 frames and each one of these with a supply pump and another booster pump, while stages 3 and 4 are configured with 3 frames.
  • The supply and booster pumps are equipped with a speed variator to adapt to the reduction in the conditions of supply pressure of the reverse osmosis.
  • The Pelton Turbines are coupled to the supply pumps of the 3rd stage for energy recovery.
  • 84% conversion.
  • Remineralisation through dosage of lime, carbon dioxide and magnesium sulphate.


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