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

• Entity: Thames Water Utilities Limited
• Location: London, Great Britain
• Capacity: 150,000 m³/day
• Type of contract: D&C
• Population served: 1,000,000 inhabitants

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.