Enhancement of Soil Aquifer Treatment to Improve the Quality of Recharge Water in the Llobregat River Delta Aquifer (LIFE ENSAT)

According to climate change predictions, Spain, as most other Mediterranean countries, faces increased water shortages, pollution and loss of water-dependent ecosystems in the near future. The Llobregat river delta aquifers - at the south-western corner of the Barcelona metropolitan area - are an important component of the system of local water resources, supplying water to the city. Overexploited in the past, they face serious ecological problems. The river undergoes severe droughts in the summertime, riparian (river bank) vegetation has disappeared, and seawater intrusion in freshwater aquifers is constant. Solutions to water stress problems are urgently needed. Yet these solutions must be sustainable, economical and safe. Managed aquifer recharge (MAR) is increasingly receiving attention, because it offers the following benefits: (1) storage capacity to buffer seasonal variations of water supply and demand; (2) protection of coastal aquifers from saltwater intrusion; (3) mitigation of the depletion of groundwater levels; (4) additional natural treatment when low quality water is recharged. The project’s overall aim is to demonstrate the application of a well-established technology for aquifer remediation such as the use of reactive barriers to enhance the degradation of recalcitrant compounds, but in an innovative way: for ‘soil aquifer treatment (SAT)’ during aquifer recharge episodes with reclaimed water, or low quality river water. Specifically, the project aims to: - Improve the quality of groundwater, at the Sant Vicenç dels Horts aquifer recharge site; - Develop a modelling tool for the prediction at the field scale of the impact of an organic substrate in terms of hydraulics and geochemistry during infiltration; - Adapt and transfer results (hydrogeochemical model and methodology for the selection, implementation and validation of the technology) to other aquifer recharge sites in Europe.