Water Quality Assessment and Hydrochemical Characteristics of Groundwater in Abhar Plain, Zanjan, Iran

In this research, the groundwater quality of Abhar Plain was studied for drinking, domestic and irrigation uses. To assess the evaluation of hydrochemistry and quality, 26 groundwater samples were collected and analyzed for the physicochemical factors such as pH, electric conductivity (EC), total dissolved solids (TDS), total hardness (TH), Na⁺, K⁺, Ca²⁺,Mg²⁺, Cl^-, SO₄^2-, HCO₃^-, CO₃^2- during Oct 2009. Groundwater suitability for domestic and irrigation purposes was assessed by using WHO standard (2004). Hydrochemical groundwater evaluations revealed that most of the groundwater belongs to the CaHCO₃ and mixed CaMgCl type. Gibbs diagram suggests that the chemical weathering of rock-forming minerals and evaporation influence the groundwater quality. The study area was evaluated for the parameters such as Magnesium Absorption Ratio (MAR), Sodium Absorption Ratio (SAR), Sodium Solution Percent (SSP), Residual Sodium Bicarbonate (RSBC), Permeability Index (PI), Kelly Index (KI) and Sodium Percent (Na%). Interpretation of these hydrochemical parameters indicates that most of the groundwater samples were suitable for drinking, domestic and irrigation uses except in a few locations.