Background Some 75% of Europe’s drinking water supplies come from groundwater. In Stuttgart the mineral water resources and springs, which are the second largest in Europe, are also extensively used in spas for medicinal and leisure purposes. Chlorinated solvents are listed in Annex II of the Groundwater Directive (GWD) as a significant groundwater pollutant because of their previously widespread use as solvents and degreasing agents. These solvents produce pollution plumes in groundwater extending up to several kilometres from the source; a common feature of industrialised and urban areas. The “prevent or limit” objective in the Water Framework Directive (WFD, Article 4) and Article 6 of the GWD protects all groundwater from pollutants. The assessment of good chemical status is carried out on a large scale for the defined groundwater bodies. However, for the protection of groundwater quality at local scale, merely a first outline is given by the Common Implementation Strategy for the WFD (Guidance-Document No. 17). The compliance-point-strategy includes monitoring point source pressures with respect to their influence on receptors (e.g. the mineral springs of Stuttgart). In order to predict groundwater quality trends and developments and to design remediation measures, contaminant plumes and large-scale pollution for entire city districts must be identified and described. Objectives The overall goal of the MAGPlan project was to develop and implement an optimal strategy for integral groundwater investigation, and to make recommendations for the efficient remediation of the key causes of pollution. The aim was to draw up a municipal groundwater management plan for Stuttgart, within the context of the WFD, to give an overview of contaminant mass-flow rates, to identify pollutant hot spots and liable causes, and to define risk management strategies and remedial action plans. Specifically, the project aimed to demonstrate innovative 3-D visualisation software and a model-based methodology, compile recommendations applicable across the EU for groundwater risk management in urban areas, and to increase awareness among the general public and the commercial sector of groundwater protection issues. Results The MAGPlan project implemented a strategy to assess groundwater contamination from point sources, and made recommendations to remedy groundwater pollution that impacts the mineral springs of Stuttgart. The project drilled 11 monitoring wells, drafted maps for groundwater visualisation, developed numerical and conceptual models, and produced remediation guidelines. Site-specific remediation measures started 30 years ago in Stuttgart removing about 25 000 kg of volatile chlorinated hydrocarbons (CHCs), but contamination in the deeper aquifers remained, with no sustained decline observed in CHC concentrations in the city’s mineral springs and spas. This indicates that the mechanisms of lateral and vertical CHC migration between the complexly-structured layers of the Keuper sedimentary rock strata and the mineral water-bearing layer of the Upper Muschelkalk sedimentary rock strata were not fully understood. The MAGPlan project applied the concept of "integral management of contaminated sites", to focus on analysing CHC migration, and the associated degradation and transformation processes, between the contamination sources and the mineral springs and spas. Due to the complex hydrogeological conditions, the project developed and implemented new and advanced investigation strategies and methods. Software tools were adapted for 3-D visualisation, with the monitoring being used to produce contour maps for all the aquifers considered. Existing data sets were analysed and combined in a conceptual (hydrogeological) model. Based on that model, a numerical model with 17 layers was built to simulate the CHC transport in groundwater. The CHC migration through rock strata layers was simulated, taking into account geological degradation and transformation processes. State-of-the-art methods are usually applied to small-scale contamination from single point sources (e.g. using single-well pump tests). The MAGPlan project, however, used an integrated quantification of total contaminant emissions, and it deployed a range of innovative tools, namely, integral pumping tests, isotopic fingerprinting, microbial degradation tests, in-situ remediation technologies, and calculation/simulation/modelling of contaminant pathways and biodegradation processes in fractured aquifers. These tools were tested and evaluated in a pioneering full-scale prototype application under real conditions. This means that the methodology can be more-or-less directly transferred to other areas where point source groundwater pollution needs to be addressed. The core deliverable was the 'Ground Water Management Plan', in which the project summarised all the results of its integral investigation of the groundwater and contaminated sites, along with the proposed measures to ensure good groundwater status. It also laid out the remediation concept and a long-term monitoring plan. This was approved by the City Council of Stuttgart, which agreed financing of €13 million until 2026. The Ground Water Management Plan became binding through the involvement of the responsible boards and agencies. The MAGPlan project considerably improved the knowledge of CHC loads and pathways, the extent of pollution plumes, the geology, and groundwater flow directions in the Stuttgart area. The information has been made available thanks to 3-D visualisation, in two films, publications, a website and workshops targeted both at experts and the general public. The project presented its finding at specialist meetings, including its final international conference in July 2015. The awareness of groundwater protection issues was raised among the public and the commercial sector through an extensive media campaign. MAGPlan contributed to the overall objective of the municipality of Stuttgart to ensure the long-term protection of groundwater and the water quality in its mineral springs and spas. Good groundwater quality is important to reduce negative impacts on human health and the environment, and the local economy surrounding spas that are used for recreational and medicinal purposes in the city. Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).