Artificial wetlands in Trosa
Since 2003 the waste water from the town of Trosa (about 4500 citizens) has been treated in artificial wetlands, after the basic treatment in the sewage plant. Thanks to the wetlands the Trosa river and the town bay have been spared from eutrophicating substances (plant nutrients) as well as contagious substances (pathogenes). Besides the value of purifying the water, the wetlands are a popular recreation area. The wetlands are used for education and many study visits are made here. Vagnhärad, the neighbouring town with about 4500 citizens, has a similar area of artificial wetlands since 2001.
Bålsta extracts waste heat
The district heating plant in Bålsta supplies Håbo municipality with environmentally-friendly heat and hot water. The plant consists of three boilers: a wood chip boiler, a pellet boiler and an oil-fired boiler, which together represent 80% of the plants total energy production. The remaining 20% are taken from a adjucent gypsum factory, whose waste heat is led to the boiler through pipes.
Congestion charges in Stockholm
The introduction of congestion charges in Stockholm was one of the reasons why Stockholm was awarded “European Green Capital 2010”. The introduction has led to reduced traffic with somewhere between 20 and 25% and that air quality has been improved, according to the Road Administration.