Final Report Summary - SEDBARCAH (Sediment biobarriers for chlorinated aliphatic hydrocarbons in groundwater reaching surface water) Polluted groundwater in urban and industrial areas often represents a continuous source of diffuse pollution of surface water. The fate of infiltrating groundwater pollutants might be influenced by the sediments in eutrophic water bodies, which form an interface between surface and groundwater and possess characteristic biological and physico-chemical degradation properties. However, relevant scientific information is scarce or non-existent. The SEDBARCAH project aimed to investigate the potential of the sediment zone to act as a barrier against the infiltration of Chlorinated aliphatic hydrocarbons (CAH) into surface water and examine whether this zone could be exploited as a sustainable and efficient biobarrier against groundwater contamination. More specifically, the project objectives were to: 1. determine the role of the sediments' microbial community in the biodegradation of groundwater pollutants infiltrating a river bed; 2. explore the boundary conditions and the possibility to increase and sustain removal activities in the sediment zone; 3. select suitable tools for monitoring such activities in situ and analyse techniques that could potentially increase the method's efficiency and; finally, 4. investigate the potential of these stimulated sediment biobarriers as a groundwater remediation technology and a surface water pollution and risk prevention technology. Therefore, a monitoring campaign was undertaken as part of the project in order to collect necessary data and identify modelling parameters. The most appropriate sampling instruments were selected and verified during this process. In addition, the composition of the 'active' sediment microbial community structure and catabolic genotypes were characterised in space and time. The degradation potential of infiltrated pollutants in the sediment zone was also investigated and degrading and dechlorinating organisms were identified. Moreover, the potential to increase CAH degradation kinetics by various amendments, such as nutrients, electron donors and electron acceptors, was explored. Finally, the reactive transport of pollutants was modelled in detail and guidelines on measuring, describing and stimulating degradation of water contaminants were developed based on the project findings. Related documents Final Report - SEDBARCAH (Sediment biobarriers for chlorinated aliphatic hydrocarbons in groundwater reaching surface water)
