POLLUTION FROM URBAN STORMWATER INFILTRATION

Stormwater infiltration in urban areas gives cause for concern with regard to the risk of soil and groundwater pollution. Compared with conventional storm drainage, infiltration introduces different and widely unknown conditions governing the impacts and the fate of the pollutants, and it is therefore difficult to assess the overall environmental impact. This paper gives a state of the art assessment of the water quality aspects of stormwater infiltration and proposes ways of managing the inherent problems. The major stormwater pollution sources are highlighted and the different processes operating in the soil and groundwater are described. The paper also discusses how the environmental risk of urban stormwater infiltration can be assessed, and outlines the possibilities for designing environmentally safe infiltration systems.