Final Report Summary - BRIDGE (Background criteria for the identification of groundwater thresholds) For the implementation of the European Water Framework Directive (WFD), Member States of the European Union are required to assess the status of their water resources and compare it with predefined quantitative and qualitative criteria. The latter are referred to as 'threshold values' (TV) and should only be determined for pollutants which cause the groundwater body, or an associated surface water body or terrestrial ecosystem, to be characterised as 'at risk'. A minimum list of potential pollutant substances to facilitate this evaluation was included within the regulation. The BRIDGE project was conducted in this context and contributed to the effort towards sharing a community approach on water management and establishing a common implementation procedure of the WFD. The specific BRIDGE objectives were to: 1. evaluate and assemble scientific outputs to set out pollution and characterisation criteria for the assessment of the chemical status of groundwater 2. derive a plausible general approach regarding the appropriate structure of relevant criteria with the aim to set representative groundwater TV which would be scientifically sound and defined at national river basin district or groundwater bode level 3. check the applicability and validity of this approach by means of case studies at the European scale 4. carry out an environmental impact assessment taking into account economic and social impacts of the methodology. The project resulted in a series of outcomes with significant exploitation potential. Firstly, a reference database was constructed. Secondly, a reference report reviewing the behaviour and effects of natural and anthropogenic groundwater pollutants for the determination of groundwater TV was produced, along with a report on the available scientific information on hydrogeological and hydrogeochemical characteristics of European aquifers for the determination of groundwater TV. Moreover, a procedure for TV setting in groundwater was developed, based on a tiered approach and on the identification of the nature of the final receptor at risk. Two reports, titled 'Sampling, measuring and quality assurance' and 'Integrated data aggregation methodology' were also prepared, to provide integrated understanding of the interdependencies between the implementation of groundwater monitoring and the derivation of groundwater thresholds. The proposed methodology was evaluated and optimised through the analysis of 14 case studies representing most of the major European aquifer typologies. Based on these findings, a methodological framework for the identification of economically efficient groundwater TV was introduced. Given that BRIDGE aimed to develop a methodology rather than a commercial product the project did not result in strictly exploitable outcomes. However, the derived procedure was anticipated to contribute towards the proper implementation of the WFD and to increase the available knowledge. Therefore, it was communicated to various interested stakeholders via a series of dissemination activities, which also ensured the establishment of linkages between scientific and policy making communities. Related documents Final Report - BRIDGE (Background criteria for the identification of groundwater thresholds)
