Assessment of Quality of drinking waterbased on the water quality index method in Hawassa Zuria Woreda, Sidama Regional State, Ethiopia
Authors: Berego Yohannes Seifu , Sota Solomon Sorsa , Ulsido Mihret Dananto , Beyene Embialle Mengistie , Debiso Amanuel Ejeso 
Published: May 2023

BACKGROUND. Ethiopia is one of the Sub-Saharan African developing nations that encounters the majority of the usual difficulties in delivering water services to its inhabitants. Thus, 60–80% of the populace is afflicted by diseases that are waterborne or connected to water. This is partly due to the shortage of access to safe water distribution systems. This study was to conduct an Assessment on Quality of drinking water based on the water quality index method in Hawassa Zuria Woreda, Sidama Regional State, Ethiopia.

METHODS. A total of twenty-three representative water samples were collected from different sources, such as two samples from the source borehole (BH), five samples from the reservoir, eight samples from storage (household containers), and eight samples from the taps. The Water Quality Index (WQI) tool was used to determine the overall condition of water quality with different physico-chemical parameters. To determine the p 0.05 significant differences in the mean values of the water quality measures at the various sampled sites and to observe the associations of variables, one-way ANOVA and correlation were used. To match the results of the heavy metal level with the WHO value, a t-test was used.

RESULTS. Bacteriological (total coliform and fecal coliforms) and physicochemical parameters such as temperature, pH, Electric conductivity, Turbidity, TDS, Nitrate, Ammonia, phosphate, Free chlorine residual, Iron, Total hardness , Magnesium, Nitrite, fluoride and Analysis of heavy metals (Mn, Pb, Zn, Co, Cu, and Ni) was done to determine their appropriateness for drinking. The study's findings demonstrated that the majority of the criteria should have been within the WHO's safe drinking water guidelines and Ethiopia's drinking water standards. However, temperature, electric conductivity, ammonia, phosphate, fluoride, lead, and nickel were among the physicochemical characteristics that in different sampling sites exceeded these safe limits. The values of temperature, turbidity and nitrate were significantly differing from the supplied source to household storage. However, other parameters showed no significant change from source to storage. The WQI values of the analyzed water samples indicate that 73.9% of all analyzed samples were excellent and 26.1% were good. The mean HPI and HEI, respectively, were 75.72 and 1.47. The average HPI score was below the threshold of 100. The average metal concentrations in drinking water were discovered to be distributed in the following order: Zn>Ni>Co>Cu>Mn>Fe>Pb. A sample t-test showed that there was an extremely significant difference (p0.01) between the GUIDELINE values and metals other than lead. The Pb/Zn elemental pair is significantly linked with each other (r = 0.524, P 0.05), in contrast to the other elemental pairs, which do not significantly correlate with one another. Pairs of Pb/turbidity are associated with one another (r = 0.715, P 0.01), according to element and physicochemical associations. Similarly, there is a significant correlation between Cu/turbidity and Cu/pH (r = -0.522, P 0.01). The relationship between EC and turbidity is also substantially correlated (r = 0.567, P 0.05).

CONCLUSION. This research strongly suggests that drinking water from heavy metal-contaminated sites should be outlawed and that lead and nickel removal should receive special attention from the appropriate authorities.