Operational use of urban drainage pollutant load models - Results from a French survey

National audienceA survey, concerning the use of both hydraulic and pollutant load models for sewers system, was conducted in 2001 among 124 French companies and organisations working in the field of sewer operation. Whereas operational uses of hydrodynamic sewer models are now very widespread, the survey underlined the low level of use of urban drainage pollutant load models. When a pollutant load model is used, mainly for sewer diagnosis and for impact assessment studies, it is usually limited to very simple approaches like multiplying a volume by a constant concentration. The application of more elaborated models is limited by the quantity and the quality of data available, the cost of these data and by the level of training needed to master such complex models. This survey confirms that there is a gap today between the tools available on the market for urban drainage pollutant load simulations and the tools that are needed, or that can be applied, by operators