A THESIS SUBMITTED TO THE FACULTY OF WATER SUPPLY AND ENVIRONMENTAL ENGINEERING, WATER TECHNOLOGY INSTITUTE, SCHOOL OF GRADUATE STUDY, ARBA MINCH UNIVERSITY, IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE DEGREE OF MASTER OF SCIENCE IN WATER SUPPLY AND SANITATION ENGINEERING

Abstract

Water quality and the risk to waterborne diseases are critical public health concerns in many developing countries. This study aimed to assess current status of the physicochemical and bacteriological quality of drinking water from sources, reservoir and consumer taps in the case of Gidole town at October and January 2022 (wet and dry season). A total of 38 water samples were collected from three different water sources such as spring water, reservoirs water and tap water. All the methods used for sample analysis were according to Standard Methods for the examination of waters and wastewaters as specified by the American Public Health Association. The physicochemical parameters namely; Temperature, Total Dissolved Solids, Electrical Conductivity, Dissolved oxygen, PH, Turbidity, Total hardness, Total alkalinity, Calcium, Magnesium, Chloride, Bicarbonate, Sodium, Potassium, Residual Chlorine, Nitrate, Sulfate, Phosphate, Fluoride and Iron was analyzed. The water quality index (WQI) was done using Canadian Council of Ministers of the Environment water quality index method. The result physicochemical parameters like Temperature, total alkalinity, total hardness, dissolved oxygen and magnesium are varies seasonal to below or above the Ethiopian and WHO standards. The turbidity of water sample in each season was below the permissible limit of Ethiopian standard but above the permissible limit of WHO guide lines. The results of the remaining physicochemical parameters are within the permissible limit of WHO guidelines and Ethiopian recommended values. The computed WQI values ranged from 58.48 to 73.53 and the drinking water quality status in the study area ranked at fair and marginal water quality. The drinking water contains high amounts of phosphate and the counts of total and fecal coliforms ranged from 5 to 24 and 1 to 6 CFU/100 mL, respectively. The results bacteriological analyses have shown that 63.2% of samples in distribution system were at medium risk and 36.8% of samples were at low risk. The study can conclude that the quality of drinking water source can be deteriorated in the water distribution systems and the water quality decline along tap water. I also strongly recommended that the current quality of water and distribution systems need to be improved or to be developed new better-quality source in order to come up with current quality problem.