POLLUTION FROM URBAN STORMWATER INFILTRATION

Stormwater infiltration in urban areas gives cause for concern with re gard to the risk of soil and groundwater pollution. Compared with conv entional storm drainage, infiltration introduces different and widely unknown conditions governing the impacts and the fate of the pollutant s, and it is therefore difficult to assess the overall environmental i mpact. This paper gives a state of the art assessment of the water qua lity aspects of stormwater infiltration and proposes ways of managing the inherent problems. The major stormwater pollution sources are high lighted and the different processes operating in the soil and groundwa ter are described. The paper also discusses how the environmental risk of urban stormwater infiltration can be assessed, and outlines the po ssibilities for designing environmentally safe infiltration systems.