Managed aquifer recharge (MAR) is stipulated by the EU Water Framework Directive to be a supplementary measure to reach good quantitative and good qualitative water status by regulating the water cycle on the basin scale within an integrated water resource management. The EU Groundwater Directive, on the other hand, prohibits any actions that may deteriorate groundwater quality – a demand which needs to be evaluated on a site-by-site basis. Within this context, emerging pollutants are of special concern, since some have shown to be poorly degradable or may only be removed under specific redox conditions.

For decades, MAR has been in use throughout Europe to replenish groundwater resources. The aim has been to supply drinking water, irrigation water or water for industrial use, as well as to establish hydraulic barriers against saltwater intrusion, land subsidence or contamination. However, when it comes to the authorization of new sites, experience in different EU countries like Germany, France and Spain has shown that authorities currently tend to follow a conservative approach, denying the authorization, especially with regard to the infiltration of treated wastewater or storm water. This is in contrast to the long-term experience in river or lake water infiltration that exists in many EU countries, where infiltration water may contain relevant amounts of treated wastewater,  emerging pollutants and contaminants of direct spills.

Therefore, as a key barrier for the deployment of water re-use schemes in Europe, especially for schemes including infiltration as additional purification step, a lack of harmonized and adequate regulation at the European level has been identified by several European research initiatives. Therefore, there is a need to provide unified European guidelines on water quality depending on the targeted reuse application, which may include managed aquifer recharge, based on strong and scientific rationales. DEMEAU will address this policy barrier through demonstrating best practices, clarifying benefits and limitations and providing recommendations related to MAR authorization.

For more information on MAR please have a look at the MAR tool box. The tool box is an information platform for Managed Aquifer Recharge (MAR) and contains theoretical considerations, guidelines for laboratory tests and field investigations, information of MAR case studies, and recommendations for a wide range of various aspects of MAR.