Hydrogeochemical Evaluation and Health Implications of Groundwater in Magura Sadar Upazila, Bangladesh: Application of GIS and Multivariate Statistics

Groundwater (GW) quality is a critical factor for its use in drinking and irrigation purpose and has become a significant concern in the southwestern region of Bangladesh. This study aims to conduct an in‐depth hydrogeochemical characterization and assess the suitability of GW for both drinking and irrigation purposes. Water samples were collected randomly from 42 tube wells and analyzed for 10 water quality parameters, along with 3 metallic pollutants, to evaluate their hydrogeochemical properties. The results of various analyses indicated that the relative concentrations of major ions follow the order: Ca 2+ > Na + > Mg 2+ > K + and HCO 3 − > Cl − > SO 4 2− . Principal component analysis suggests that the hydrogeochemistry of the GW in the study area is primarily influenced by both geogenic processes (such as weathering and leaching of host rocks) and anthropogenic activities (including the use of agrochemicals, sewage sludge, and municipal solid waste disposal). The water quality index indicated that approximately 38% of the water sources were classified as good, 28% as poor, 10% as very poor, and the remaining 24% were unsuitable for drinking purposes. The Piper diagram reveals that the predominant GW types were Ca 2+ ‐HCO 3 − (80%) and Ca 2+ ‐Na + ‐HCO 3 − (20%). A notable finding from this analysis was that basalt weathering—via surface runoff into aquifers—was the dominant process contributing to GW mineralization, along with silicate weathering, carbonate weathering, and ion exchange. Additionally, agricultural practices have a significant impact on the mineralization process. The hazard index indicates that approximately 40.5% of adults and 90.48% of children were exposed to high noncarcinogenic risks due to the use of contaminated water. Alarmingly, both adults and children were facing significant carcinogenic risks from the same exposure. According to the irrigation water quality index, parameters such as total hardness, Kelly’s ratio, and sodium adsorption ratio indicate that approximately 50% of the water sources were unsuitable for irrigation. Therefore, based on these findings, Magura Sadar Upazila requires targeted spatial management to ensure a safe drinking water supply and promote sustainable agricultural practices.