Assessment of Drinking Water Quality for the Case of Hawassa City in Sidama Regional State, Ethiopia

Abstract

Water quality and the risk of water-related diseases are a serious public health problem in many developing countries like Ethiopia. The aim of the study was to assess the drinking water quality from source to household tap water and it was conducted in Sidama Regional State, Southern Ethiopia, Hawassa city. The Study area map and sampling points were prepared using Arc GIS 10.4 and QGIS respectively. 21 water samples were collected to characterize and analysis drinking water quality parameters. 11 water samples from sources, 4 from service reservoirs and 6 from tap water were taken. The main physio-chemical parameters analyzed for the study were Total Dissolved Solids (TDS),Temperature, Turbidity, Electrical conductivity (EC), pH, Fluoride, Nitrate (No3), Total Hardness (TH), Calcium and Magnesium, Phosphate, Sulphate, residual chlorine and Microbiological (Total Coliform and coliform/CFU).The results were determined using on site measurements and laboratory experiments. The result of the finding was compared with the WHO and Ethiopian water quality standards and it shows that most of the water quality parameters tested are within the standard of WHO and National drinking water quality standards. However, there are some physio-chemical parameters (Temperature, Turbidity, fluoride and residual chlorine) that are not inconformity with the standards. The mean temperature at the source, reservoir and tap water was 22.01oC, 22.5 oC and 21.83 oC respectively. The turbidity levels for source samples ranged from 10 to 45 NTU, with a mean of 24.5 NTU, which was higher than the WHO's recommendation of less than 5NTU.High Fluoride content (3.9mg/l ) was recorded from BokoAlamura well which is above the permissible limit of WHO and NDWQS. Therefore, the water sector should use DE fluorination technology or minimizing use of this source for drinking purpose to minimize the risk at the consumers. There was no free residual chlorine in the tap water sample which indicates there might be recontamination of the water till consumption. On the other hand, the results depicts that Hawassa drinking water supply did not contain total and feacal coliform for all samples analyzed, which might be because the sources are properly protected from contamination and sufficient treatment for the water before distribution. The overall WQI was also determined for water source, reservoir and tap water sample and it was found 89, 71 and 69.7 respectively. Therefore, Based on the WQI result the Hawassa drinking water quality is good for source and fair at reservoir and tap water.