Hydrogeological Features and Environmental Impacts of Geothermal Waters in the Yildiz River Basin (Sivas, Turkey)

Abstract

The study area, located in the Yildiz River Basin (Sivas), has eight geothermal waters, which are used for balneotherapy. The aim of this study was to investigate the natural and/or anthropogenic water pollution in terms of drinking and irrigation water in the Sicak, Cermik, Uyuz, Cermigi, and Hamzaseyh, Cermigi geothermal areas. Na+, Cl-, SO4-2, B, Mn, Fe, As, and Se concentrations of the geothermal waters generally exceed the upper limits stated in the Turkish Standards for Water Intended for Human Consumption and World Health Organization regulations. Based on the irrigation water classification by the U.S. Salinity Laboratory Diagram, it is concluded that these waters may have hazardous levels of salinity and sodium when used as irrigation water. Wastewater from these health and tourism centers is discharged into the Yildiz River and to agricultural land. This procedure causes increase in the concentrations of major and minor elements and negatively affects the river water quality.