Evaluation of Ground Water Quality with Water Quality Index (WQI) in Woreillu Town, Ethiopia

The present work is aimed at assessing the water quality index (WQI) for the groundwater of Wreillu town.The groundwater samples were collected from selected locations within one-year-monitoring period from January to August 2019. All the laboratory measurements of the physical, chemical and heavy metal parameters were measured using the standardized method. The WQI of the study ground water was established from ten physicochemical parameters (temperature, pH, Conductivity, Turbidity, Total alkalinity, TDS, TH, Nitrate, Phosphate, and Sulphate) and five heavy metals (Fe, Cu, Pb, Mn and Zn). The result showed that all physical and chemical parameters were almost below the maximum allowable level based on the WHO standards for drinking. On the other hand, the lead (Pb) was exceeded the maximum allowable limit in all the studied locations based on the WHO standards for drinking water. The computed WQI values range from 49 to 136. Therefore, out of 5 studied locations, one location was classified in the “Excellent water” class, one location as a “Good water” class, three as a “Poor water” class. Furthermore, lead, pH and turbidty were considered the most effective parameter on the determination of WQI in this study. The study revealed that only a few of the values for the heavy metals and physico-chemical parameters of the water samples were above the tolerable limits recommended by the WHO. This calls for regular monitoring and purification of boreholes to ensure good water quality. Keywords: water quality index, drinking water, physico-chemical parameters, heavy metal DOI: 10.7176/JEES/11-1-02 Publication date: January 31 st 2021