Why Do Some Water Utilities Recycle More than Others? A Qualitative Comparative Analysis in New South Wales, Australia

Abstract

Although the recycling of municipal wastewater can play an important role in water supply security and ecosystem protection, the percentage of wastewater recycled is generally low and strikingly variable. Previous research has employed detailed case studies to examine the factors that contribute to recycling success but usually lacks a comparative perspective across cases. In this study, 25 water utilities in New South Wales, Australia, were compared using fuzzy-set Qualitative Comparative Analysis (fsQCA). This research method applies binary logic and set theory to identify the minimal combinations of conditions that are necessary and/or sufficient for an outcome to occur within the set of cases analyzed. The influence of six factors (rainfall, population density, coastal or inland location, proximity to users; cost recovery and revenue for water supply services) was examined for two outcomes, agricultural use and "heavy" (i.e., commercial/municipal/industrial) use. Each outcome was explained by two different pathways, illustrating that different combinations of conditions are associated with the same outcome. Generally, while economic factors are crucial for heavy use, factors relating to water stress and geographical proximity matter most for agricultural reuse. These results suggest that policies to promote wastewater reuse may be most effective if they target uses that are most feasible for utilities and correspond to the local context. This work also makes a methodological contribution through illustrating the potential utility of fsQCA for understanding the complex drivers of performance in water recycling.

Identifying Drivers of China's Provincial Wastewater Reuse Outcomes Using Qualitative Comparative Analysis

“…; Kunz et al. ; Lazarova et al. ; Tsai and Chou ) and belong to the social and natural categories of wastewater reuse drivers identified by Kunz and colleagues ().…”

“…We expect that lower per capita water availability and a higher urban population indicate a higher water stress (Kunz et al. ), and that this will be an important factor that contributes toward wastewater reuse.…”

“…Proximity to sea is argued to be an incentive for relaxed wastewater treatment and discharge standards, because it allows for a cheap way of discharging wastewater (Kunz et al. ). The other access‐related conditions are availability of urban green space and access to agricultural land.…”

“…; Kunz et al. ; Ragin ). Configurational comparative methods are designed for intermediate‐N sample sizes (10 to 50) and focus on understanding the causal relations between conditions and a given outcome, that is, what conditions are sufficient and necessary to the presence of certain outcomes (Ragin ).…”

“…In particular, QCA takes into account conjunctural causation , that is, certain outcomes are a result of combination(s) of conditions instead of a single factor, equifinality , that is, the same outcome could be explained by different paths and combinations of conditions, and causal asymmetry , that is, the presence of an outcome is not explained by the same factors that explain the absence of an outcome (Kunz et al. ; Ragin ). These features are potentially important to understand the often complex and multifaceted wastewater management outcomes (Kunz et al.…”