Groundwater residence times and contaminant transport in the Gardermoen aquifer

The Gardermoen aquifer has been object for extensive research in recent years, however the efforts have been focused on the upper part of the aquifer. There is limited knowledge on deep groundwater at Gardermoen in particular, and in Norway in general. Es pecially regarding renewal of the groundwater resources, and long term effects of pollution on groundwater quality. The existing scientific work on the aquifer system, and installations already present there, makes it an excellent site for closing this ga p of knowledge, by drilling and sampling deep groundwater. Dating these water samples, combined with chemical analyses will yield data on water quality and corresponding age, as well as groundwater velocities, enabling estimates of risks for - and effects of - groundwater pollution due to future loads of potential contaminants. By implementing previous research in the area, we will calibrate regional groundwater flow and transport models and develop methods for sampling BAT-wells for noble gases and 3H+3Hetri. This dating method has only been tested to a limited extent in Norway, but a few sample analyses indicate that the method in highly applicable. The project will contribute to imp rove tools(models) and methods(data aqusition), thus enabling sustainable groundwater management and increasing water safety.