Case studies of the economic, environmental, and social impacts of direct potable reuse

Direct Potable Reuse (DPR) is increasingly being considered as one of many possible water supply options for water utilities in various locations throughout the US. However, as with any new water supply, it needs to be considered vis-à-vis other technologies or solutions, including a ‘no action’ scenario to determine the true value and economic impact of that supply option. To improve public acceptance and stakeholder support, it is critical that such comparisons be completed in a transparent, publicly accessible manner to facilitate not only management-level decision making but also public engagement and education about the water supply options. This calls for a comprehensive and objective evaluation methodology for comparing alternative water supply options, which fits in nicely within a triple bottom line (TBL) framework. The triple bottom line assessment (TBL) framework provides an established accounting approach for concurrently quantifying economic, environmental, and social implications for any business decision or project. At a time when companies or other organizations are expected to operate on the basis that long-term profitability should go hand-in-hand with social justice and environmental protection, TBL offers the ideal framework to ensure sustainable decisions. For water and wastewater utilities and other water-related authorities, TBL represents a widely accepted, transparent, and defensible means to compare the total (economic, environmental and social) benefits and costs of any investment vis-à-vis other alternatives, including the option of taking no action. Through a WRRF-funded study, we have developed a specialized TBL tool and associated methodology that goes beyond conventional practices, drawing upon the social sciences to provide quantitative measures of social indicators and drawing upon input-output lifecycle assessment to quantify environmental impacts. The framework also engages stakeholders throughout the process but provides accountability and transparency during decision making. Working within an established TBL framework, we are using hands-on participatory workshops and case studies to define, test, and validate a methodology for comprehensive evaluation of the various supply options that incorporates stakeholder perceptions and value systems. As part of this project, we developed a series of case studies in the US and Australia to test the TBL framework and to demonstrate its use in comparing various water supply options including DPR and IPR. The case study sites include facilities/communities in the Mid-Atlantic, Southeast, and West Coast regions of the US in addition to communities along the Eastern and Southern coasts of Australia. In this presentation we will discuss the developed framework, demonstrate how it can be used in evaluating water supplies, and show results from several of the case study sites in the US and Australia.