Soil and groundwater pollution from urban stormwater infiltration

The aim is to document how stormwater infiltration affects pollution mass flows in urban environments. This is partly done through mass balancing and use of simulation models for pollution transport, and through field-investigations of infiltration systems that have been in function for decades. A field study was conducted during 1994-95 in Switzerland, focusing on excavating existing surface and sub-surface infiltration systems for road runoff and investigating their ability to retain or break down contaminants such as heavy metals and polyaromatic hydrocarbons (PAH). Of primary interest is identification of conditions that favour retention and immobilisation of contaminants inside and directly below infiltration structures. The future perspective is sustainable management of urban stormwater.