The aquifer media data was obtained from drilled borehole information from the GTK-Lähde database and the SYKE-POVET database. For the areas that lack drilled borehole information the aquifer media was based on the base sediment of the superficial deposit maps of Finland at scales 1:20 000 and 1:200 000 from GTK. The lower resolution 1:200 000 superficial deposit map covers the whole country, while the higher resolution 1:20 000 superficial deposit map covers only 44.3% of the country. The map scale 1:20 000 was first used for the interpretation and where the data was not available at 1:20 000 scale the 1:200 000 scale data was applied.