HYDROGEOCHEMICAL CHARACTERIZATION AND ASSESSMENT OF GROUNDWATER QUALITY IN SATAME RIVER CATCHMENT, SNNPR, ETHIOPIA

Abstract

Groundwater is one of the most valuable natural resources for human survival and economic development on earth and over the world. In the study area, groundwater is the main water resource for various purposes such as drinking, agriculture and industrial. The study was conducted in South Nation Nationality People Region, Kembata Tembaro zone Satame river catchment. The aim of this study was to evaluate the hydrogeochemical description and assessment of groundwater quality suitability for different purposes. For the purpose of this study twenty one water samples were collected and additionally nine secondary water quality data from previous work were used from boreholes, shallow wells, hand dug wells and springs. Fifteen parameters were analyzed for partial physico-chemical composition of groundwater such as Electrical Conductivity (EC), Hydrogen Ion Concentration (pH), Total Dissolved Solids (TDS), Temperature (Temp), Sodium (Na+), Potassium (K+), Calcium (Ca2+), Magnesium (Mg2+), Bicarbonate (HCO3-), Carbonate (CO3-) Sulfate (SO4-2), Chloride (Cl-), Nitrate (NO3-), Fluoride (F-) and Iron (Fe2+). The Ethiopian Standards Agency and World Health Organization water standards were used as the basis of evaluating the suitability of groundwater for drinking purposes. Electrical Conductivity (EC), Sodium Percent (Na %), Sodium Adsorption Ratio (SAR) and Permeability Index (PI) were used to evaluate suitability of water for irrigation purpose. In the study area, the Calcium and bicarbonate are the dominant cations and anions, respectively. The order of abundance of major ions in the groundwater Ca2+>Na+> Mg2+>K+ for major cations and HCO3->SO4-2>Cl->NO3- for major anions. Three water types were identified by using piper diagram from that Ca-HCO3 is dominant water types. The groundwater evolution in the study area was mainly controlled by rock – water interaction as identified using Gibbs pilot. However the study indicates that the groundwater in most of the water samples results in the study area is generally suitable for drinking and irrigation purpose.