Sustainability Metrics: Applications for Water Utility Planning

Sustainability assessments are value-based, descriptive processes that may be used as a basis for making decisions such as the size, location, timing, and cost of new facilities, as well as for prioritization of recommendations. These protocols can be either qualitative, quantitative, or both. In most cases, present sustainability metrics are associated with triple bottom line evaluations, and the sustainability criteria are divided into economic, social, and environmental categories. However, some utilities use sustainability evaluation criteria that do not easily fall into these categories. Sustainability assessment practices and associated metrics have been reviewed for a geographic cross-section of water and wastewater utilities, including information from those in Australia, the United Kingdom, and the United States. An evaluation of practices and their applicability has been used to derive guidance on the metrics most appropriate for use in different situations.