Occurrence of hexavalent Chromium in Drinking Water in Schleswig-Holstein

Abstract

The concentration of hexavalent chromium in drinking water from 196 groundwater treatment plants in Schleswig-Holstein was analyzed. 68 % of the samples showed Cr-VI concentrations below 0.02 µg/l. The highest concentration was 1.34 µg/l. The Cr-VI concentration was found to be higher if lime or related substances were used in the treatment process. Closer investigations of a plant treating oxygen rich groundwater showed that the raw water already contained 80 % of the Cr-VI found, while about 20 % of the Cr-VI derived from lime used in the process. The additional health risk arising from Cr-VI in the drinking water analyzed in this project was negligible (<1:106) or in specific cases slightly higher but still minor.