The European Union Drinking Water Directive aims to protect human health and promote safe water consumption. The 2020 revision, Article 17 in particular, directed member states to provide public access to information on drinking water. This update was a response to citizen initiatives calling for the active participation of end-users in water services and greater transparency from water utilities. Difficulties implementing previous versions of the directive have highlighted divergences between policy purposes, local capacity to implement, and public response. These divergences are explored within eight case studies in Nordic countries and analysed using the policy implementation framework. We employed a mixed-method, multi-stage approach. Policy formulation was characterized through a literature review, policy design by the synthesis of legislative instruments, and policy implementation via an analysis of delivery behaviour based on interviews. We identified the main drivers of the directive's update and contrast these with the ongoing implementation process in the countries of study. Our results point to a differential and highly contextual implementation, which differs from the primary drivers of the policy update, namely, the establishment of public confidence in water services.