An efficient initialization strategy is developed in this work to solve the NLP and MINLP models forsynthesizing water-using networks with multiple contaminants. A fairly good estimate of the optimal solutioncan be generated for any given problem according to a simple calculation procedure. Two published examplesare adopted to demonstrate the effectiveness of the proposed approach. The optimum solutions obtained inthis study are at least as good as those reported in the literature, while the computation time required toachieve convergence is significantly less.