Occurrence and distribution of hexavalent chromium in ground and surface waters in Cyprus under the CrITERIA project

The origin and distribution of hexavalent chromium, Cr (VI) over four seasonal cycles was investigated through a conceptual model that included three aquifer systems in Cyprus. An extensive water sampling grid covered two areas of known sea water intrusion of the local coastal aquifers, namely the Kokkinochoria (Area 1) and Kiti (Area 2) and the mountainous ophiolite complex of Troodos (Area 3). Sources of anthropogenic contamination of Cr (VI) were investigated through sampling points in proximity to agricultural and industrial environments. Analytical results give a good insight in the presence of Cr (VI). Samples from the Kokkinochoria (Study area A1) and Kiti (Study Area A2) areas exhibit high conductivity nitrate concentrations (due to NPK fertilisers and seawater intrusion). The highest Cr (VI) value of 25 μg/l is observed in the Troodos area (Study area A3) where Cr(VI) is observed in all types of water systems (surface, ground and spring). The highest mean value, however, is exhibited in Kiti-Pervolia. Stable isotope analyses show strong deuterium versus Cr (VI) correlation with distinct differentiation between the types of water systems. Troodos shows two distinct groups of meteoric and near meteoric water whereas isotopically enriched water is shown to correspond to the Kiti and Kokkinochoria area.