A two-stage procedure is proposed for the minimisation of wastewater. In the first stage, heuristic rules are used to find the initial feasible flowsheet; in the second stage, the flow rates of streams in the initial flowsheet are determined by mass balance of the contaminants. The operations considered in this work include re-use, regeneration, mixing and bypassing of water streams. The proposed procedure is simple and the results of the examples studied are comparable with or better than those found in the literature.