From Near Surface Geophysics to Groundwater Reservoir Characterisation and Establishment of New Water Work

The public water supply in the municipality of Varde in the southwestern Jutland, Denmark, is threatened by poor water quality.

Contents of pesticides in shallow unprotected aquifers, high iron content especially in buried valley aquifers, saltwater issues in some deep aquifers and organic content (brown water) in Miocene aquifers and aquifers related to interglacial layers have forced the water supply to find new aquifers with good water quality in the Varde area. It has been difficult to fully understand the complex geological settings formed by glacial tectonics with huge impact on near surface geology.

In the past 10 years airborne and ground based electromagnetic geophysical surveys have been carried out. The results have been followed up with drillings in the Vittarp area located 10 km northwest of Varde. These investigations have finally provided valuable information, and the detection, of the around 135 m deep buried Vittarp valley with a deep and well protected aquifer which fulfils the demands to excellent water quality and quantity.