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 Trondelag (Central Norway), the Hvaler archipelago and other areas around Oslofjord (Southeastern Norway). A dear relationship is demonstrated between many chemical parameters and lithology or geographical location. The parameters electrical conductivity, Cl-, SO42-, 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 Trondelag. 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.