ASSESSMENT OF THE QUALITIES OF SPRING AND WANKAWATERS, ESTIE DISTRICT, SOUTH GONDAR ZONE, ETHIOPIA

Abstract

Level of physicochemical parameters, nutrients and selected heavy metals of Estie Densa spring water and Wanka river water samples were investigated. There is no available information on the levels of these parameters in the study area so far. The physicochemical parameters were measured using multimeter and nutrients were measured using portable photometer 7100 whereas heavy metal analyses were determined by FAAS, after wet acid digestion. A total of seven water samples were collected from the selected sampling sites. The accuracy of the digestion procedure was evaluated using spiking experiments; where excellent recovery (92.7% to 99.8%) were obtained. The range of physicochemical parameters found in water samples were pH (6.4 - 8.1), Electrical conductivity (9.9 - 90μS/cm), total dissolved solute (TDS (4.8 - 44.8 mg/L), Turbidity (4 - 315 NTU), Total alkalinity (1600 - 6800 mg/L), Temperature (21.3 - 28.6 ), Chlorine (35.6 - 213 mg/L), Phosphate (0.14 - 0.7 mg/L), Sulphate (1- 4.25 mg/L), Ammonia (0.23 - 0.595 mg/L), Nitrate (1.2 - 11.8 mg/L) and Nitrite (0.015 - 0.139 mg/L). Among these parameters only the level of turbidity was above the permissible limit except in one site. The level of heavy metals (mg/L) in water samples were Mg (0.42 - 1.29), Ca (1.14 -2.4), Cr (0.512 - 0.985), Mn (0.007 - 0.02), Ni (0.304 - 0.732), Fe (0.5 - 0.71), Pb (0.485 - 0.567) and Cd (0.042 - 0.111). Among these elements the concentration of Cr, Fe, Cd and Pb were above the permissible limit of WHO. There is significant difference (p < 0.05) in mean values of all nutrients, three of the metal (Mg, Ca and Cd) and physicochemical parameters, except alkalinity in all the seven study sites. The levels of Fe, Pb, Cd, Cr were higher than the permissible limit of WHO that might have risk for the consumers. From the studied, it can be generalized that the spring and wanka river water samples are not safe for drinking due to high level of heavy metals. Thus, it needs further treatment and control of the level of these metals before consumption and application for agricultural uses.