Double-porous infiltration

Double-porous infiltration is a type of surfacing which treats polluted rainwater. When the water has passed through the surfacing, it can be used or conveyed directly into watercourses or the nearest harbour, thereby relieving sewers and treatment plants (this type of technology is also called LAR).

Double-porous infiltration functions by having the water pass through a series of filters comprised of several layers of mats, one on top of the other. From an inflow chamber, gravity causes the water to pass through a layer of chalk filter, after which it is collected in an outflow chamber. There are no chemicals or mechanical parts to this technology, and its is fairly easy to run.

The technology has been successfully tested at a large pilot plant in the public urban park, Byparken, in Ørestaden. Double-porous infiltration was developed collaboratively between Copenhagen Energy (now HOFOR), City & Port Development, City of Copenhagen, Realdania, Rambøll and the University of Copenhagen.