Material reuse/recycle is gaining much attention in recent years for environmental sustainability reasons and the rising costs of fresh resources as well as waste treatment. The advent of process integration techniques for water network synthesis is among the most active area in the past decade. Via in-plant water reuse/recycle, fresh water and wastewater flowrates are reduced simultaneously. However, most focus to date has been dedicated to single pure fresh water source (without impurity). In this work, problems for single and multiple impure fresh water feed is addressed using the numerical targeting tool of water cascade analysis (WCA) technique. A three-step procedure is proposed on the modified WCA technique, which leads to the minimum pure and impure fresh water sources.