A Multicriteria Model for the Assessment of Source Water Contamination by Anthropogenic Activities to Support Land Use Management

Many anthropogenic activities release pollutants that can find their way to drinking water sources, potentially impacting human health and water treatment costs and causing environmental depletion in watersheds. Planning and management of land use are therefore necessary to protect drinking water sources, an essential and complex endeavour. Regulatory frameworks often require identifying and evaluating land parcels with activities that should be controlled or forbidden. In order to support these tasks, we developed a sociotechnical multicriteria evaluation approach, based on ELECTRE III, for assessing the contamination potential of parcels. By incorporating stakeholders’ values and different types of data (quantitative, qualitative, and spatial), this novel approach is a comprehensive way for assessing potential threats to drinking water sources. It was applied in Quebec City, Canada, and led to a spatial decision support system currently used operationally by the municipality. It is generalizable and can be adapted to other watersheds. It helps decision-makers in prioritizing field inspections in the watershed in order to apply source water protection actions where needed.