Evaluating Groundwater Pollution Using Hydrochemical Data: Case Study (Al Wahat Area East of Libya)

Abstract

Water is one of the most challenging current and future natural resources, which will directly affect the environment and development by the changes in its quantity, quality and regional distribution. However, Water quality is the critical factor that influences human health and irrigation proposer. This work aims to investigate hydrochemical analysis and geochemical processes influencing the groundwater of Al Wahat area (Jalou, Awjla and Jukherra), which is located in central east Libya. Thirty four water samples collected from domestic and agricultural water wells were analyzed and used for conventional classification techniques which were Piper, Durov and Stiff diagrams to evaluate geochemical processes. Cluster analysis was used to identify the water type and ions concentration and distribution. Results show significant increase of dissolved salts, especially Nitrates. Elevated nitrates concentration can be attributed to either the disposal of untreated sewage water from disposal ponds and septic tanks or the infiltration of irrigation water saturated with fertilizing chemicals. Therefore, irrigation wells revealed that suffering from nitrate contamination caused an increase of the chance of nitrate pollution. In addition, contour maps present a sudden increase in the total dissolved salts (TDS) in the northeastern part coincident with the highest of secondary ions of NO3 content, indicating the infiltration of irrigation water which is responsible partially for the groundwater degradation. Hydrogeochemical facie is NaCl type and enrichment of Na+ and Cl− can be attributed to urban untreated wastewaters and high rate of evapotranspiration. The concentrations of heavy elements such as Zn, Pb, Cu, Cd, Ni and Cr were low and within the WHO ranges.