GROUND WATER QUALITY INVESTIGATION IN MEJO TOWN FOR DRINKING PURPOSE USING WATER QUALITY INDEX AND SANITARY INSPECTION

Abstract

Water is a dynamic source for human existence. Clean drinking water is a basic need for good health and a basic human right. The objective of the study was to assess the suitability of water source for drinking using water quality parameters and sanitary survey of at the Mejo Town Sidama Region, Ethiopia. For water quality analysis, eight sampling sources were selected and sampling was done three times for each source (August-September 2021) during rainy season and during dry season (January-February 2022). Different physicochemical and bacteriological parameters were determined for all water samples following standard methods. Sanitation inspection was done according to WHO procedures using risk of contamination (ROC) to predict possible contamination of the water source in the catchment areas. The results of the study showed that most analyzed physicochemical parameters were within safe limits set by WHO and Ethiopian standards, but the temperature at all sampling points was above the allowable limit. Microbiological analysis confirmed the absence of coliforms at four of the sampling sites. The presence of coliforms in the other four samples (S_1, S_5, S_6 and S_7) indicates that measuring the number of coliforms is a manageable, very low risk. Weighted arithmetic water quality index determined for water source samples at different sampling sites. Fourteen parameters were taken into account to calculate such as: Turbidity, T0, EC, pH, TH, Na+, K+, Mg2+, Ca2+, Cl-, HCO3 -, SO4 2-, NO3- and TDS and the value of sampling sites was ranged between (25.30-34.22) and categorized in Class B (Good) water quality status. The result obtained from the sanitary inspection revealed that 12.5%, 37.5%, 25% and 25% of the water sources were found to be ‘low’ ‘intermediate’ ‘high’ and ‘very high’ contamination risk category. The Pearson correlation coefficient matrix between the main physico-chemical parameters of the water sources of the study area showed a close significant positive link. From the stiff diagram, water samples showed mainly bicarbonate and calcium-magnesium type aquifers. The results of this study point out that protected water sources used by the community in Mejo were exposed to coliform contamination that is health concern. Community awareness raising, better management and protection of sources, improvement of sanitation and regular water quality monitoring and domestic water treatment before consumption are possible solutions to reduce health risks in the area.