Natural concentrations of major and trace elements in some Norwegian bedrock groundwaters

Twenty-eight groundwater samples have been collected from boreholes in bedrock aquifers in Nord Trøndelag (Central Norway), the Hvaler archipelago and other areas around Oslofjord (South-eastern Norway). A clear relationship is demonstrated between many chemical parameters and lithology or geographical location. The parameters electrical conductivity, Cl −, SO 4 2−, F −, Na, Al, Fe, Be, Bi, Cd, Cu, La, Mo, Pb, Th, Tl, U, Y, Zn, Zr, B, Rn, and Si have generally higher values in the Iddefjord Granite of Hvaler, while pH, alkalinity, Ca, Mg, Cs, Rb, and Sr are highest in Trøndelag. Several parameters such as F −, Na, Fe, U, Rn and possibly Al exceed drinking water norms on Hvaler. Measured values of the analyzed parameters compare well (except F −) with the Dutch “A” (background) values, developed for assessment of anthropogenic contamination. The authors warn, however, against uncritical use of “norms” developed in countries with other dominant lithologies than Norway.