BACTERIOLOGICAL QUALITY AND PHYSICO-CHEMICAL CHARACTERISTICS OF WELL AND RESERVOIR WATER IN DILELATOWN,SOUTH WEST SHOA ZONE, OROMIA REGIONAL STATE, ETHIOPIA

Water is a natural resource and is essential to sustain life. Poor drinking water quality has been linked to several diseases of man particularly in developing countries where availability of potable water is a big challenge. Thus, this study was conducted to assess the bacteriological and physico-chemical quality of well and reservoir water in Dilela town. A total of 19 water samples were collected from protected well, unprotected well and reservoir. The bacteriological quality of water from these sources was analyzed using the membrane filtration method. The analysis demonstrated that all the water samples in the study area contained aerobic mesophilic bacteria, coli forms, faecal coli forms, and E.coli. The mean counts of aerobic mesophyllic bacteria, total coli form and fecal coliform ranged from188-240 CFU/100ml, 66-- 180 CFU/100ml, and 30-60CFU/100ml respectively. In addition, the mean value of physico-chemical parameters such as EC, TDS, temperature, pH, fluorides, sulphate, nitrate, phosphate, turbidity, dissolved oxygen and biological oxygen demand of the well water were 322437, 161-218mg/l,17-19,5-6,0.06-0.08mg/l,24-49mg/l,0.09-1.1mg/l, 0.2-0.9mg/l, 1.515NTU, 0.2-0.mg/l, 139-mg/l respectively. The study revealed that all water samples did not meet the acceptable bacterial limits of safe drinking water set by WHO and Ethiopian standard ( ES) guidelines. In addition, the physicochemical analysis also showed that most of the parameters evaluated were within the range recommended by WHO guidelines for drinking water samples with the exception of temperature, pH, turbidity and dissolved oxygen which exceeded the WHO standards. On the basis of these findings, recommendation is made to responsible bodies of Dilela town to implement effective water management and treatment methods to produce bacteriological safe well and reservoir water in the area.