Abstract
In this study, the hydrochemical characteristics, drinking water suitability, and potential human health risks of groundwater in the Karapınar region (Kemaliye, Erzincan, Türkiye), which has become a critical drinking water resource due to drought associated with climate change and the depletion of surface water resources, were investigated using an integrated multiparameter approach. Within the scope of the study, a total of 18 water samples, comprising 13 spring water samples and 5 groundwater samples obtained from wells, were collected during the dry season (October 2021) and analyzed for major ions, physicochemical parameters, nitrate, and trace elements. The suitability of the samples for drinking purposes was evaluated using the water quality index (WQI), while carcinogenic and noncarcinogenic health risk assessments were performed according to U.S. EPA guidelines and supported by geographic information system-based spatial analyses. The principal aquifer system within the approximately 150-km2 study area consists of Miocene-aged clayey limestones and associated clastic units. Volcanic intrusions within these formations contribute to a complex geological framework that influences groundwater flow patterns and hydrogeochemical evolution. Piper and Schoeller diagrams indicate that groundwater is predominantly of the Mg–Ca–HCO3 type, with hydrochemical evolution primarily controlled by carbonate weathering. The nearly parallel Scholler patterns further suggest a common hydrogeochemical origin and similar water–rock interaction processes across the aquifer. Trace element analyses revealed that Fe, Mn, As, Ni, and local Pb concentrations exceeded the standards for drinking water at several sampling locations. WQI results indicated that 39% of the groundwater samples could be classified as “good quality,” whereas 61% ranged from “poor” to “unsuitable” for drinking purposes. Health risk assessment results demonstrated unacceptable noncarcinogenic risks for children and elevated carcinogenic risk levels at multiple locations. The findings provide critical insights for sustainable groundwater resource management under increasing climate-induced water stress and emphasize the need for continuous monitoring of geogenic contaminants to protect public health.