Stormwater infiltration and accumulation of heavy metals in roadside green areas in Göteborg, Sweden

Abstract

To avoid the negative effects of the traditional stormwater treatment by drainage into separate or combined sewers, various methods for local stormwater treatment have been introduced, often referred to as ecologically adapted solutions. Stormwater infiltration in urban green areas is a frequently used method. With infiltration, the pollutants contained in the stormwater are, to a great extent, accumulated in the soil profile. Theaccumulation of heavy metals in the topsoil of urban green areas with infiltration of stormwater runoff from roads is compared with that in adjacent green areas with no stormwater infiltration. The topsoil layers of urban roadside areas in Göteborg, Sweden, are polluted by heavy metals. The concentrations of Zn, Pb and Cu are about 2 to 8 times higher than in natural rural areas in Sweden. Concentrations of metals in infiltration areas were, on average, 200% higher than in reference areas.