Voluntary agreements and systemic lock-in in the circular economy: The certification of sewage sludge in Sweden

Abstract

This chapter departs from the dual objective of reusing waste while at the same time mitigating pollution; it focuses on the opportunities and challenges of managing this trade-off through voluntary agreements between various actors. The chapter aims to investigate and discuss the emergence, outcomes, and future challenges of the Swedish voluntary certification scheme REVAQ. This scheme includes efforts among wastewater treatment plants (WWTPs) to build trust for the application of sewage sludge on agricultural land and thus reuse the nutrients contained in it, not least by reducing the presence of metals and organic substances. Our findings suggest that the establishment of REVAQ was, in many ways, a natural response of the incumbent actors to an uncertain regulatory situation. The preventive environmental work pursued because of the certification scheme has been successful, thus resulting in decreased flows of hazardous substances to soil. However, REVAQ faces challenges, largely due to previously unattended trace elements, e.g., microplastics and pharmaceutical residues. These will make it difficult for actors to convince the key stakeholders about the future quality of the sewage sludge. There is also currently a prioritization of system optimization over system change, i.e., a bias towards incremental improvements in the existing system instead of seeking to innovate beyond this system. REVAQ likely contributes to this path dependence and technological lock-in.