APRIORA tackles the need for a risk-based prioritisation of quaternary treatment at wastewater treatment plants (WWTP) to mitigate emission of micro-pollutants with focus on active pharmaceutical ingredients (API). Since WWTPs are the main emission pathway to the environment, the new proposal for Urban Wastewater Treatment Directive (UWWTD) demands a mandatory quaternary treatment to be implemented in all WWTP > 100.000 PE until 2030 and a risk-based prioritisation of advanced treatment for WWTP between 10.000-100.000 PE. Accordingly, regional environmental protection authorities (EPAs) in charge will have to prioritize risks and propose cost-effective mitigation measures for future investments in cooperation with WWTP operators. However, both target groups lack sufficient information, capacities and tools to do so: API emissions from WWTPs are not measured, concentrations in surface waters are only available on few selected monitoring sites; no consistent tools for the demanded risk assessment (RA) or à priori effect assessment of potential mitigation measures exist. APRIORA addresses these deficits by providing a RA capacity program (1) combining effective monitoring, modelling and multi-criterial RA, an (2) open-source GIS environment, and (3) a capacity building programme to apply (1) + (2) in everyday working practices. Along with BSR-wide transfer + training activities, APRIORA contributes to an efficient strategic water management that improves the state of BSR waters.