The overall objective of the project was to support the European Commission in an assessment of impacts of a range of options for the review of the Urban Waste Water Treatment Directive (UWWTD) . This overall objective was achieved through the delivery of a series of tasks aiming at the definition of an impact assessment methodology, the collection of thematic information to inform the analysis of impacts and performing the actual analysis of impacts.As indicated in the evaluation report of the UWWTD , the Directive has been very effective overall and will be even more effective once it is fully implemented. Despite the positive gains made through the application of the Directive there remain areas for improvement. The impact assessment investigated 16 areas of improvements including: stormwater overflows and urban runoff, smaller agglomerations, sensitive areas, energy efficiency, micropollutants, circular economy, waste water surveillance and access to sanitation. Cost-benefit analyses were conducted to assess the most suitable options per area of improvement, and recommend a final policy optino package for the revision of the Directive.