A Research Agenda for the Future of Urban Water Management: Exploring the Potential of Nongrid, Small-Grid, and Hybrid Solutions.

Recent developments in high- and middle-income countries have exhibited a shift from conventional urban water systems to alternative solutions that are more diverse in source separation, decentralization, and modularization. These solutions include nongrid, small-grid, and hybrid systems to address such pressing global challenges as climate change, eutrophication, and rapid urbanization. They close loops, recover valuable resources, and adapt quickly to changing boundary conditions such as population size.

The cost of hybrid waste water systems: A systematic framework for specifying minimum cost-connection rates.

To determine the optimal connection rate (CR) for regional waste water treatment is a challenge that has recently gained the attention of academia and professional circles throughout the world. We contribute to this debate by proposing a framework for a total cost assessment of sanitation infrastructures in a given region for the whole range of possible CRs. The total costs comprise the treatment and transportation costs of centralised and on-site waste water management systems relative to specific CRs.

Economies of density for on-site waste water treatment.

Decentralised wastewater treatment is increasingly gaining interest as a means of responding to sustainability challenges. Cost comparisons are a crucial element of any sustainability assessment. While the cost characteristics of centralised waste water management systems (WMS) have been studied extensively, the economics of decentralised WMS are less understood.

Emerging solutions to the water challenges of an urbanizing world.

The top priorities for urban water sustainability include the provision of safe drinking water, wastewater handling for public health, and protection against flooding. However, rapidly aging infrastructure, population growth, and increasing urbanization call into question current urban water management strategies, especially in the fast-growing urban areas in Asia and Africa. We review innovative approaches in urban water management with the potential to provide locally adapted, resource-efficient alternative solutions.

Barriers to Innovation in Urban Wastewater Utilities: Attitudes of Managers in California.

In many regions of the world, urban water systems will need to transition into fundamentally different forms to address current stressors and meet impending challenges-faster innovation will need to be part of these transitions. To assess the innovation deficit in urban water organizations and to identify means for supporting innovation, we surveyed wastewater utility managers in California. Our results reveal insights about the attitudes towards innovation among decision makers, and how perceptions at the level of individual managers might create disincentives for experimentation.

To connect or not to connect? Modelling the optimal degree of centralisation for wastewater infrastructures.

The strong reliance of most utility services on centralised network infrastructures is becoming increasingly challenged by new technological advances in decentralised alternatives. However, not enough effort has been made to develop planning tools designed to address the implications of these new opportunities and to determine the optimal degree of centralisation of these infrastructures. We introduce a planning tool for sustainable network infrastructure planning (SNIP), a two-step techno-economic heuristic modelling approach based on shortest path-finding and hierarchical-agglomerative clustering algorithms to determine the optimal degree of centralisation in the field of wastewater management.

Beyond User Acceptance: A Legitimacy Framework for Potable Water Reuse in California.

Water resource managers often tout the potential of potable water reuse to provide a reliable, local source of drinking water in water-scarce regions. Despite data documenting the ability of advanced treatment technologies to treat municipal wastewater effluent to meet existing drinking water quality standards, many utilities face skepticism from the public about potable water reuse. Prior research on this topic has mainly focused on marketing strategies for garnering public acceptance of the process.

Institutional trajectory for diffusing on-site wastewater treatment in urban China.

Urban water scarcity has been an issue for a long time in China while water pollution has attracted more and more attention over the last two decades. Recently, on-site wastewater treatment (OST) has been proposed as a meaningful alternative to deal with both water pollution and water scarcity in cities in a more sustainable way. However, the diffusion of such an OST system is still slow and often hindered by mismatched regulation, city planning and policy interventions.

The Innovation Deficit in Urban Water: The Need for an Integrated Perspective on Institutions, Organizations, and Technology.

Interaction between institutional change and technological change poses important constraints on transitions of urban water systems to a state that can meet future needs. Research on urban water and other technology-dependent systems provides insights that are valuable to technology researchers interested in assuring that their efforts will have an impact. In the context of research on institutional change, innovation is the development, application, diffusion, and utilization of new knowledge and technology.

A compatibility-based procedure designed to generate potential sanitation system alternatives.

Regarding multi-criteria decision analysis (MCDA), the problem of generating alternatives has not received the attention it deserves. Most research is currently devoted to the problem of alternative selection, where it is assumed that a set of appropriate alternatives is already given. This paper addresses the generation of potential alternatives in the domain of sanitation systems planning and decision-making.

Future scenarios for a sustainable water sector: a case study from Switzerland.

Uncertainties about the long-term prospects of urban water management systems have increased substantially over the past decade due to an increasing variety of regulations, technologies, and demand structures. In Switzerland, this uncertainty is mirrored by growing difficulties of utility managers and (waste)water scientists to agree on shared strategies: Water professionals demand support for pressing management problems, while researchers fundamentally question the longer-term sustainability of the established water management system. To reestablish shared orientation, we conducted a foresight study for the Swiss (waste)water sector in 2004.