This paper develops a new method and computer software to design the water-using networks of multiple contaminants by combining the concentration potential concepts (Liu et al., 2009. AIChE Journal 55, 374-382) with a Linear Programming (LP) method. The precedence order of the process units is determined by the values of the Concentration Potential of the Demands (CPDs). The allocations from the sources to the demands are decided with the LP method. To reduce the consumption of high quality sources, each source is assigned a weighting factor, which is obtained based on the values of the Concentration Potential of Sources (CPSs). The results of a few illustrated examples obtained with the presented method are comparable to that obtained with the mathematical programming algorithms in the literature. Compared to the literature methods, the method proposed in this paper has the following characteristics: initial values are not required, and the calculation is simple. (C) 2011 Elsevier Ltd. All rights reserved.