Assessment of groundwater quality in the diyarbakir organized industrial zone

The quality status of groundwater resources in and around the Diyarbakır Organized Industrial Zone (DOSB) was investigated, and their usability for drinking and irrigation purposes was evaluated. Groundwater samples collected from five different locations were subjected to physicochemical and biological analyses, and the obtained results were compared with national and international standards. The parameters analyzed included pH, electrical conductivity (EC), nitrate, nitrite, sodium, and heavy metals.The results of the analyses revealed that industrial activities have significant impacts on groundwater quality, and in some locations, the direct use of groundwater for drinking purposes may pose health risks. Hydrogeochemical evaluations indicated that most of the waters are of the Ca–Mg–HCO₃ type, although in certain samples transitions were observed due to sulfate and chloride contributions. Piper diagram results demonstrated the influence of evaporitic formations and saline aquifer contributions on water composition. According to the Wilcox diagram, most of the waters fall within the "suitable – very suitable" category for irrigation, while some samples require careful use due to elevated Na% values. The USSL diagram indicated that sodicity risk is generally low; however, samples with high salinity levels may cause long-term soil salinization problems.Overall, it was concluded that groundwater in the study area is generally suitable for agricultural irrigation. Nevertheless, in the case of long-term use, measures such as drainage practices, soil reclamation techniques (e.g., gypsum application), and the selection of appropriate crop species are recommended to mitigate salinity and sodicity risks. The study emphasizes the necessity of developing effective waste management strategies in industrial zones, implementing regular hydrogeochemical monitoring programs, and promoting environmental awareness policies. Keywords: Groundwater, Industrial pollution, Water quali, Diyarbakır OIZ