Saltwater intrusion in drilled wells is a big problem in coastal areas in Sweden. A new method VLF-R is tested to delineate the boundary between fresh and salined water. In Switzerland a special construction of VLF-instrument has been developed by Dr. Müller. The aim of the invstigation was to test Dr. Müllers instrument, its applicability in Swedish rocktypes. Syrveys were carried out at three sites in the Stockholm - Sweden archipelago. Results: * At a survey with three frequencies: 20 kHz, 50 kHz and 200 kHz, we have obtained good information of fractures at various dephts as well as of saline and fresh water aquifers. * By multidirectionary measurements 2 or 3 or more from the same point, it is possible to distinguish the principal aligment.