Rejlers has entered into an extensive collaboration with the Käppala Association to modernise the Käppala plant on Lidingö and increase its capacity. The project will run until 2028 and is expected to yield results in the form of significantly reduced emissions of nitrogen, phosphorus and organic matter, which will contribute to a cleaner Baltic Sea. The Käppala plant on Lidingö currently treats wastewater from more than 500,000 inhabitants and businesses in eleven municipalities north and east of Stockholm.

To cope with stricter emission conditions and increase capacity, the plant is being rebuilt and upgraded with a new biological purification process. The increased capacity provides the member municipalities with new growth opportunities. Rejlers is responsible for designing all electrical power, general power and lighting, control and automation as well as process electricity in the Käppala 900k project - the large project of the upgrade, which will be completed by 2028.

Work is currently underway in various disciplines within the project, where several of Rejlers' divisions and the wholly-owned subsidiary Eurocon collaborate and contribute expertise. As the plant continues to be operational during the modernisation and workspaces are limited, innovation is required in the form of finding feasible solutions. Particular emphasis has therefore been placed on coordination between all parties involved in the project.