Circularity indicators for remediation activities: assessing circularity at the ex-ante and ex-post phases in compliance with the latest standards

The sector of contaminated soils and groundwater remediation is a critical and complex one, that requires targeted interventions and integrated strategies to reduce and mitigate the health and environmental risks posed by contamination, while adhering to principles of sustainability and circularity. The objective of this paper is to provide a set of suitable indicators for assessing circularity in the context of contaminated sites remediation both in the ex-ante and the ex-post remediation phases. Indicators have been selected from those provided in the latest standards for circularity assessment, specifically UNI/TS 11820:2022 and ISO 59020:2024. The selection process involved an in-depth analysis of the indicators included in the aforementioned standards and their data requirements, which serve as the knowledge base for a working group of experts with interdisciplinary expertise in remediation technologies design, Life Cycle Assessment, and Multi-Criteria Decision Analysis, which selected the circularity indicators suitable for application in contaminated sites remediation processes. The selected indicators follow the SMART model of criteria, which requires that they all are specific, measurable, achievable, relevant and time-bound. This selection procedure identified a total of 24 circularity indicators applicable in the ex-ante and the ex-post phases. These indicators cover the key dimension of material, energy, and water resource efficiency and aim to support informed decision-making and monitoring, with a structured and measurable basis for the integration of circularity aspects into contaminated sites remediation.