In the middle of Aarhus lies Eskelund, an old refuse dump, where more than 2 million cubic metre of waste have been dumped. The dump is a problem for part of Aarhus’ drinking water supply, as the refuse dump is placed directly above an aquifer supplying the nearby waterworks. ALECTIA, the Region of Central Jutland, GEUS, and the University of Aarhus have teamed up around a project clarifying whether the seepage of toxins from the refuse dump area is a threat to the groundwater.

ALECTIA has developed a sophisticated and highly targeted model that simulates the spread of pollution from the dump. Nearby lies Hørløkke dump, where ALECTIA conduct similar studies of pollution threat from this dump. These investigations are conducted for the Region of Southern Denmark.

At present, there is no seepage; however, the future changing climate poses a risk to old and former refuse dump areas, such as Eskelund. The heavier rainfalls, which most likely will come in the future, could result in the toxins being washed out to a greater extent than earlier. Therefore, so-called geo-electrical datings, pumping tests, and other hydrological examinations are carried out. The results combined with the climate data in a groundwater model showing whether there is a threat to the groundwater. The results of this will probably be ready by the end of the year.

In consultation with the Region of Central Jutland, ALECTIA has chosen to use the new up-and-coming modelling tool HydroGeoSphere (HGS), which is distinguished by being a fully integrated modelling tool, i.e. HGS calculates water and contaminant transport in both water courses, unsaturated zones (soil layers above groundwater level) and saturated zones (soil layers below groundwater level) with the same equation system.

ALECTIA considers HGS to be the first representative of the next generation of modelling tools. We expect that we will need our experiences with HGS when assessing other consequences of the climate changes and in the further work with the water plans.

The examinations are part of a larger EU research project, CLIWAT (Climate Change and Water) mapping the consequences of the climate changes as regards water in different locations.