Influence of the geochemical environment on fresh water trace element levels in Greece.

In Greece, the main sources of drinking water supplies are groundwater aquifers. It has been shown that mainly in Northern Greece, Eastern Thessaly region and Peloponnese, problems occurred due to the presence of an excess of trace elements in the groundwater. Some of the results obtained will be presented. High boron values have been found in drinking water all over Greece due to natural sources, geothermal activity and/or seawater. In the province of Thessaloniki (Northern Greece) and in Eastern Thessaly, natural arsenic has been detected in groundwater and may derive from reductive dissolution of As-rich Fe oxyhydroxide present in the aquifer. In the Northwest Peloponnese, inhabitants are drinking a Fe-Mn contaminated water due to the geological formations of the aquifers. These findings have important implications for water management. In a setting of high natural geochemical background values, source control of the pollution is not possible and water managers have to cope with a local to regional geochemical anomaly that implies specific water treatment or mixing with unpolluted resources to bring concentrations down. [ABSTRACT FROM AUTHOR]