Decision support tool for establishing an action plan aiming to decrease the discharge of micro pollutants into sewage system networks

Abstract : The innovative decision support tool assists in ranking pollution sources and different urban watersheds, based on potential local emissions and the sensibility of the receiving water bodies. The potential local emissions are calculated by coupling characteristics of pollution sources to data bases containing potential emission coefficients of micro pollutants:, 1) Industrial/artisanal activities: APE (principal activity code) - emission (kg/year) by substance and by APE (mean values from national and local data bases): 2) Stormwater runoff: surface type (from national data bases and interpretation of satellite pictures) - emission (kg/year) by substance and by type of surface (literature data) and dependent on typical local rainfall: 3) Domestic: number of habitants - emission (kg/year) by substance and by habitant (literature data). The level of (eco) toxicity of each substance allows to transform potential emissions in potential pressures (PP). The hydraulic model of the sewage system network allows to affect parts of the local potential pressures to the water body. For each water body, a sensibility index (SI) is calculated based on its physico-chemical characteristics and its functions. The ratio PP/SI allows for ranking pollution sources. The coupling to a data base describing solutions for emission reduction for different pollution sources (substitution, treatment, education,..) will allow elaborating an action plan associated to a socio-economic evaluation.