COALITION PROJECTS IN WASTEWATER TREATMENT: THE CASE OF A DRINKING WATER RESERVOIR IN THE CZECH REPUBLIC

The paper presents an optimisation model developed for a drinking water reservoir on the Vrchlice River, which is a sub-basin of the Elbe river basin located in the Czech Republic and Germany. Two scenarios for achieving environmental targets were formulated by specialists, together with an assessment of the costs of the projects. In both scenarios implementation of common wastewater treatment plants was considered. In the first scenario, standard water treatment technology was assumed and the treated water was transported outside the watershed. In the second scenario, advanced technologies were implemented and the treated water remained in the watershed. The optimum solution for 26 polluter-municipalities, where 121 coalitions can be considered (individual and joint wastewater treatment plants), was computed. The results have shown that the coalition projects (joint wastewater treatment plants) have potential to reduce social costs and the optimisation model is able to find such solution. The results also suggest that the modelling method presented has the potential to increase the role of economic considerations in the early stages of planning and decision-making about water treatment programs/projects.