An integrated approach to least-cost planning of water reuse schemes

Fresh water supplies throughout the world have been getting scarcer over the past few decades. Population and industrial growth leading to an immense increase in the number and intricacy of sources of water pollution, climate change, and shifts in weather patterns towards extremes are just some of the factors that are making the option to reuse water more attractive throughout the world, and necessary for some regions. While there are numerous obstacles to be overcome in planning water reuse schemes, the costs of treatment and distribution are two of the most important factors that need to be considered at the planning level. An additional factor, the selection of end users, also can have significant impact. New decision support software for integrated water reuse, called WTRNet, has been developed, which incorporates these three factors in determining the least-cost design alternatives. A brief overview of existing tools relevant to water reuse is presented, followed by a thorough description of key software features. An application of the WTRNet software on a case study involving a small number of potential industrial users of reclaimed water is presented, which demonstrates the importance of utilizing formal optimisation in determining the most promising design alternatives.