An assessment of the availability of pollutant constituents on road surfaces

The quality of stormwater runoff from the urban environment is of increasing concern to urban communities and, consequently, greater emphasis is now being placed on the management of stormwater quality. An essential need for this management is information about the drainage system and the impacts of alternative management approaches. This information, typically, is obtained through the use of catchment model systems which simulate the processes which influence both the quantity and quality of stormwater runoff. These model systems consist of a number of components with information flowing from one component to another; each of these components in turn comprised of process models. An important component of these systems for water quality modelling is the generation component where the mass of pollutant constituent available for transport during the storm event is estimated. Available information for use in the models applied to this task is extremely limited and, consequently, the poor reliability of this initial information is reflected in the reliability of the predictions obtained from the catchment model system. Presented herein are the results of a study investigating the build-up of pollutant constituents on a suburban road in the eastern suburbs of Sydney, Australia. It was found that the pollutant constituents available for transport during storm events were significantly different from previously published data for North America. Furthermore, it was found that both rain and wind events lowered the available pollutant constituent mass on the road surface.