CORONA, Confidence in forecasting of natural attenuation as a risk-based groundwater remediation strategy.

The overall goal of CORONA is to increase confidence in assessment and forecasting of natural attenuation (NA) of groundwater pollution. M&R DTU collaborates with several European partners (http://www.shef.ac.uk/corona/) and together we will carry out multi-disciplinary research on 6 varied field sites and in the laboratory and use numerical modeling. The activities done by M&R DTU are primarily connected to a field site where landfill leachate infiltrates to an underlying sandy aquifer. This creates a reduced plume, with manganese and nitrate reducing conditions close to the landfill. Different phenoxy acid herbicides are the main pollutants in the leachate. These compounds are recalcitrant in the anaerobic core of the plume, but the hypothesis is that a significant mass reduction (by microbial degradation) occurs at the fringe of the plume, where aerobic water from the surrounding aquifer mixes with the contaminated water. This hypothesis will be tested by field observations (mass fluxes through control planes as well as high resolution multi-level-samplers) and laboratory investigations (micro-scale variations in fringe sediment cores of phenoxy acid degradation potential, microbial numbers and redox chemistry). The experimental results will be incorporated in a reactive solute transport model for the site.