Influence of policymakers and civil society stakeholders on sewage sludge management strategies: Empirical results from European utilities.

Sewage sludge management is crucial for water utilities to move towards a circular valorisation of resources. The current literature focuses mainly on the technological aspects of sludge management strategies. However, the current discussion of these strategies does not consider possible pressures arising from the utilities' civil society stakeholders and from policymakers. To fill this gap, this paper develops a conceptual framework, based on the current literature, that identifies the utility's key decisions on sludge management strategies (valorisation route, overperformance and vertical integration), and links them to possible pressures arising from civil society and existing regulations. Subsequently, the study validates the framework through a multiple explanatory case study, investigating the empirical relevance of such pressures in six water utilities across Europe. The influence of citizens and municipalities is found to be crucial in the choice of sludge valorisation routes. Economic instruments, command and control instruments and, new to the literature, regulatory uncertainty are found to be key policy features influencing utilities' decisions on sludge management. The paper provides a first-of-its-kind investigation that highlights the mechanisms through which policymakers and civil society stakeholders shape utilities' sewage sludge management strategies. The results complement and extend existing theoretical knowledge on the role of institutional pressures in the implementation of sustainable environmental systems.

Adoption of water reuse technologies: An assessment under different regulatory and operational scenarios.

Water reuse technologies may alleviate the water scarcity problems that affect many world regions, but their adoption is still limited. In particular, key actors in the adoption of water reuse technologies are water utilities, that provide both urban water and wastewater treatment services. Water utilities are embedded in the urban water system, which includes several stakeholders (urban water users, citizens at large, the environment) that may drive or pose barriers to water reuse adoption. Therefore, to ensure a smooth introduction of water reuse technologies, it is fundamental to understand how water reuse interacts with the existing urban water system and impacts its stakeholders. This paper contributes to the ongoing debate on water reuse by conceptualizing the interaction between water reuse technologies and the urban water system and its stakeholders, and addressing the adoption decision of water utilities by assessing its economic and environmental consequences. Based on a review of literature, policy and other secondary documents, and on primary data coming from interviews with experts from a water utility operating in Southern Italy, the study models the utility's response to a shift from urban to reuse water. It then simulates how reuse water introduction impacts on the utility and other stakeholders of the water system, under various regulatory and operational scenarios defined through a thorough analysis of policy documents and literature. Results show that the adoption of water reuse reduces the utility's margin by cannibalizing urban water demand, but appropriate policy measures may enhance the economic sustainability of reuse. System-level performances, such as impact on freshwater savings, costs for users, effects on the public budget, are also assessed, showing how different regulatory options moderate the intensity of impacts for the different stakeholders of the water system. Furthermore, the adoption of reuse water by the most distant users is found to enhance the economic sustainability of reuse and positively impact the utility's margin.