The information is collected daily from satellite images that are analyzed. In the event of high concentrations, warnings are sent out. The service is the result of an EU-funded project in which the company behind the app has participated together with, among others, Lake Mälaren's water management association.

- Lake Mälaren has a long history of problems with algal blooms and eutrophication. There are just over three million people living around Lake Mälaren and using it as a swimming lake and recreation. It is also the lake we take most drinking water from and it is also a problem for the waterworks with algal blooms, says Ingrid Hägermark, head of the Mälaren water management association.

Extra eyes on bathing and drinking water

Several municipalities and waterworks have started using the app, which is called Cyanoalert. In the Stockholm area, Huddinge municipality keeps an extra eye on the algae situation at bathing sites. Stockholm water, which delivers drinking water, also uses the app. There you see the advantage that with the warning service you are quickly warned about algal blooms and can act on the same day with, for example, sampling.

There is already satellite monitoring of algal blooms in the sea, including the Baltic Sea, but not in lakes, writes Swedish Radio Ekot, which was the first to tell about the new service.

The trial extends during 2020 and 2021 and will then be evaluated.