Kola Ecogeochemistry: Groundwater investigations

Abstract

The chemical composition of 185 groundwater samples collected from two catchments in the extreme NE of Norway and NW of Russia over the periode April 1994 to November 1995 is reported in terms of Ag,A1,As,B,Ba,Be,Bi, Br,Ca,Cd,C1,Co,Cr,Cu,F,Fe,K,Li,Mg,Mn,Mo,Na,Ni,NO3,P,Pb,PO4,Rb,S,Sb,Se,Si, SO4,Sr,Th,Ti,T1,U,V and Zn concentrations (as determined by ICP-MS, ICP- AES and IC), pH and electrical conductance. One catchment (C2) is located in Russia 5 km downwind of the nickel-copper ore smelting industry in Monchegorsk, which is a major So2 and trace metal emission source, the other (C5) is located in Norway 30 km off-wind from the nickel-copper ore smelter in Nikel and 52 km off-wind from the nickel-copper ore roasting plant of Zapoljarniy, which are also significant emitters of inorganic atmospheric pollutants. Groundwater chemistry mostly reflects the mineralogi- cal composition of the gabbro aquifer in C2 and the Quaternary deposits in C5,although groundwater in C2 also shows signs of incipient contamination from surface waters (heavy metals, sulphate, chloride). However, only the median value of Ni concentration in groundwater from C2 exceeds published 'background' groundwater compositions. WHO, CEC and U.S.EPA drinking water standards are all (well) above any detected concentration in C2 or C5 ground- water, excepts for A1, Fe and MN. Groundwater in C2 has been acidified by S- compounds emitted from Monchegorsk, but the groundwater's capacity to neutra- lise incoming acidity has not been exhausted. In C5, groundwater has not been acidified to any extent and has a high acid neutralising capacity. This study demonstrates that the geological substrate of a catchment is a fundamental control on how groundwater responds to anthropogenic manipulation, even of the most severe magnitude.