Capacity improvement of the Henriksdal wastewater treatment plant in Sweden

Stockholm is one of Europe's fastest growing cities, and with a steady population increase, it also imposes greater demands for water purification, while higher demands for cleaner water are imposed by the Baltic Sea Action Plan and the EU Environmental Directive. To cope with future wastewater treatment needs, the system needs to be renovated to maintain the water quality in Lake Malar and the Baltic Sea.

In light of this, Stockholm Vatten AB has decided to renovate the wastewater treatment plant in Henriksdal to accommodate future needs and environmental requirements. Stockholm's wastewater treatment thus urgently needs to be renewed.

We constructed a 400 metre long access tunnel for Stockholm Vatten in order to renovate the water basins for their future capacity improvements. The project is part of the groundwork for upgrading the treatment plant. The access tunnel was blasted beneath the plant's water basins and subsequently renovated with the aim of enhancing the capacity increase.

The construction of the tunnel was a complex infrastructure project because it took place in a vibration-sensitive environment. In addition to the plant's staff, all pumps and pipes in the vicinity, which includes residential areas, a protected historical burial site, day-care and schools must also be taken into account. This kind of work requires thorough risk analyses and the right knowledge of the work.

The access tunnel project started in January 2016 and was completed according to schedule in the summer of 2016. The rebuilding and capacity improvement of the Henriksdal wastewater treatment plant is expected to be completed in 2025. The initiative means above all that the water in the Lake Malar will be even cleaner and there will be fewer contaminants discharged into the Baltic Sea.


Henriksdal wastewater treatment plant
Stockholm Vatten AB