The harbour turns blue in Copenhagen: The Harbour Baths

The idea of swimming in Copenhagen’s harbour would have been out of the question fifteen years ago. Close to 100 overflow channels fed wastewater into the harbour making the water heavily polluted.

We addressed the problem by investing in a complete modernisation of the sewage system. The water quality improved, and the City of Copenhagen was able to open the public harbour baths. Today the harbour is one of the trendiest spots in the city. In the summer and spring, the area is bustling with BBQ parties, couples strolling along the pier and students, families and businessmen having a swim in the heart of the Danish capital.

A combination of innovative solutions created a clean harbour.

  • Mechanical, biological and chemical wastewater treatment: Removes nutrients, salts and minimises discharge of heavy metals.
  • Combined sewer reservoirs: Reservoirs with connecting conduits store wastewater until there is capacity in the sewage system.
  • Decoupling of rainwater: The utility provider operates a reimbursement scheme, in which a landowner connected to the sewage system is reimbursed a connection fee if the rainwater is decoupled and discharged locally.
  • A three-tiered sewage system: This new sewage system is established in new urban districts. The system has already proved very effective against flooding
  • 55 overflow channels closed: Wastewater is only discharged to the harbour during particular heavy rainfall.
  • Automatic warning system: By calculating and monitoring the bacteria level, the system identifies whether it is safe to swim. An online forecast is available on the city’s website and as and app.

Follow the links below to learn more about the solution and how it was made possible.

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Amalie Østergaard
+45 2121 7399