Case Studies of Economic Analysis and Community Decision Making for Decentralized Wastewater Systems

This report was submitted to the National Decentralized Water Resources Capacity Development Project. It examines how communities consider and value the benefits and costs of different scale wastewater facility options (on-site, cluster, and centralized options) in monetary or other terms, and examines the driving issues, motivations, thought processes, and decision-making methods of stakeholders relative to choices of wastewater system scale. Case studies of eight U.S. communities cover seven topics that have received little attention in the literature to date. These include: financial benefits of incremental capacity expansion through implementation of decentralized systems; impacts of wastewater system choices on community growth, development, and autonomy; implications for fairness and equity within communities; how communities evaluate the performance and reliability of wastewater systems; how wastewater system planning affects relationships in a community and how relationships and trust affect wastewater decision making; hydrologic impacts of wastewater systems; and the value of decentralized systems to sanitation utilities that already manage large centralized systems. The case studies examine how each community evaluated the topical issue in the wastewater facility decision-making process, or in some cases how the issue came up after wastewater facility decisions were made. The report also includes an analysis for a hypothetical community of the financial benefits of incremental capacity expansion using decentralized systems compared to periodic large-scale investments in centralized capacity.