A Decision Support System for the Design and Evaluation of Sustainable Wastewater Solutions Brent C. Chamberlain, Giuseppe Carenini, Gunilla O ¨ berg, David Poole, and Hamed Taheri Abstract—The drive toward sustainable wastewater management is challenging the conventional paradigm of linear end-of-pipe solutions. A shift toward more sustainable solutions requires that information about new ideas, systems, and technologies be more readily accessible for addressing wastewater problems. It is commonly argued that decision-making needs to involve engineers and other community representatives to define values and brainstorm solutions. This paper describes a decision support system (DSS) prototype that is designed to help community planners identify solutions which balance environmental, economic, and social goals. The system is designed to be scalable, adaptable, and flexible to allow fair assessment of new ideas and technologies. It supports the exploration of consequences of various alternatives and visualizes the tradeoffs between them. Our DSS takes in modular descriptions of components and a description of a community context, automates the design of alternative wastewater systems, and facilitates evaluating how well each design satisfies the given context. It provides an adaptable platform from which new solutions can be designed without having to predefine how a single component fits within a specific system. Our DSS facilitates the exploration of alternative solutions by visualizing the effect of various tradeoffs and their consequences in relation to the community’s sustainability goals. Index Terms—Constraint-based processing, decision support, design, emerging technologies, environment, interoperability Ç 1 INTRODUCTION A linear, end-of-pipe infrastructure design has domi- nated wastewater management in the western world since the industrial revolution [1], [2]. Population growth and urbanization in combination with concerns related to resource scarcity and global change have sparked an interest in more sustainable and cyclic approaches [3], [4], [5]. As a consequence, the past decades have seen a rapid growth of innovations based on the idea of waste as a resource rather than a liability, with a focus on water, energy, and nutrients. The uptake of technical and institu- tional innovations is, however, slow. This is in part because the liability costs of public and environmental health may be significant. The slow uptake may also partly be due to the siloed institutional frameworks which are geared to augment supply (e.g., by building larger pipes) rather than to manage demand (e.g., by introducing low flush toilets). The challenge of providing robust management of domestic and industrial sewage is becoming increasingly urgent as the majority of sewage infrastructure in the industrialized world will require retrofitting and replacement in the near future and more than half of the people living in megacities in the developing world lack access to centralized sanitation services [6], [7]. Growing costs in combination with environmental concerns and the challenges involved in securing the quality and quantity of water heighten the urgency of the issue. It has been repeatedly shown that successful implementa- tion of robust wastewater management solutions is intri- cately tied to environmental, social, economical, and political aspects at different scales and thus requires active engage- ment of a variety of experts, in addition to wastewater engineers [6], [8], [9]. Identifying “the most sustainable solution” involves finding solutions that minimize negative effects, while maximizing benefits for local and global environments. The challenge is considerable; it is context- dependent and multidimensional in which competing objectives must be identified and tradeoffs made. Decision makers are scrambling to identify the “best solution” for their specific context: but they simply do not have sufficient resources to carry out an integrated analysis, and they generally settle on the traditional solution [10], [11], [12]. Guest et al. [12] discuss the challenges with sustainable wastewater management, and that it is necessary to bring in multiple perspectives when identifying possible solutions. Decision support systems (DSSs) can, for example, be designed to allow input from different parties involved in the decision making process as planners navigate through complex problems [13]. Several DSSs have been developed to aid decision making in wastewater management [14], [15], [16], [17], [18], [19]; see [20] for a review. According to Hamouda et al. [20], most DSSs focus almost exclusively on the technical and economic aspects of wastewater, while IEEE TRANSACTIONS ON COMPUTERS, VOL. 63, NO. 1, JANUARY 2014 129 . B.C. Chamberlain is with the Department of Landscape Architecture/ Regional and Community Planning, Kansas State University, 302 Seaton Hall, Manhattan KS, USA 66506-2902. E-mail: brentchamberlain@ksu.edu. . G. O ¨ berg and H. Taheri are with the Institute for Resources, Environment, and Sustainability, The University of British Columbia, 2202 Main Mall, Vancouver, B.C. Canada V6T 1Z4. E-mail: goberg@ires.ubc.ca, hamed.taheri@alumni.ubc.ca. . G. Carenini and D. Poole are with the Department of Computer Science, The University of British Columbia, 2366 Main Mall, Vancouver, B.C. Canada V6T 1Z4. E-mail: {carenini, poole}@cs.ubc.ca. Manuscript received 2 Oct. 2012; revised 20 Feb. 2013; accepted 18 May 2013; published online 27 June 2013. For information on obtaining reprints of this article, please send e-mail to: tc@computer.org, and reference IEEECS Log Number TCSI-2012-10-0740. Digital Object Identifier no. 10.1109/TC.2013.140. 0018-9340/14/$31.00 ß 2014 IEEE Published by the IEEE Computer Society