Kapellbäcken is one of the most polluted streams in Västerås. Stormwater from the Erikslund shopping centre, the E18 motorway and the Hacksta industrial estate flows into the stream.
The City of Västerås and Mälarenergi AB have built a new wetland park in order to purify the waters of Kapellbäcken. Particles sink to the bottom in the ponds at the wetland park, becoming trapped there, and nutrients are absorbed by plants. By the time the water is discharged from the wetland park to Lake Mälaren, up to 60 per cent of the heavy metals and nutrients have been removed.
The wetland park is multifunctional – it serves a number of purposes. Apart from purifying water, it provides an important aquatic habitat for birds, insects and plants. There is now a rich everyday natural environment here where people can enjoy walks and days out, and a living classroom where schoolchildren can get really close to the teeming life in the water.