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5 September 2014

Spectacular Outdoor Wastewater System

The Wetland Alhagen, Nynäshamn

Photo Credit: Stockholm International Water Institute (SIWI)

Photo Credit: Stockholm International Water Institute (SIWI)

This large wetland of 28 hectare is the final step of a waste water treatment (following mechanical and chemical processes). The wetland was built instead of retrofitting the existing plant by conventional methods for nitrogen removal, a choice that has been found very wise. Learning from 15 years of operation, it has been proven that the wetland is not only an efficient treatment system but also has saved much capital and energy costs.

The wetland purifies water from nitrogen, phosphorus and bacteria, so the water released into the Baltic Sea is near natural water quality. The wetland rely on a very simple technology, were water is intermittently filling and emptying large shallow ponds densely covered with emergent and submerge plants.  The treatment is sun and gravity driven and no sludge is produced.   Besides being an efficient treatment step the wetland is an appreciated recreation area for residents and a well-known site for bird watchers around Stockholm.

The visit will allow you to hear about the background of the wetland as well as getting the best insights from the facility creators and managers.   Get to know all about the process, the maintenance, the purification results, costs and energy aspects.

This trip is currently SOLD OUT!


From 5 September 2014 at 11:15 to 5 September 2014 at 16:00