PHYSIOCHEMICAL AND MICROBIAL QUALITY OF DRINKING WATER, A CASE OF NEGELE ARSI WEREDA, WEST ARSI ZONE, OROMIA REGIONAL STATE, ETHIOPIA

Water is natural resources and is essentially 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 biological and physico-chemical quality of drinking water at NegaleArsiWoreda.A total of 72 water samples were collected from deep well water. The analysis demonstrated that all the water samples in the study area contained aerobic mesophyllic bacteria, total coli form and fecal coli forms.The mean value of aerobic mesophilic bacteria, Totalcoliform and fecal Coliform bacteria.count of the four kebeles were aerobic mesofilic bacteria (log CFU/ 1 (9.33 ± 0.10, 10.45±0.37,8.43 ± 0.50 and 11.63 ± 0.6) (14.08 ± 1.10, 13.62 ± 1.30, 6.6 ± 0.48 and 12.041 ±0.25) (20.23 ± 0.50 5.30 ± 0.5515.98 ± 0.83 22.04±0.08 ) respectively . In addition the mean value of physic-chemical parameter such as electron conductivity, temperature pH,nitrate ,turbidity ,chlorine of the deep weel water were (3.9±0.85 ,5.77±0.16, 1.32±0.15,2.11±0.15)15.24±0.11,18.5±0.042.2.05±0.2,15.5±5)(20.57±0.11,23±0.52,19±0.53,21±0.33)(6.82±0.25,7.22±0.74,6.9±0.13,7.2±0.91) respectively. The study showed that all water samples did not meet the acceptable bacterial limits of safe drinking water set by World Health Organization and Ethiopian Standard guideline .In addition the physic-chemical analysis also showed that most of the parameters evaluated were within the range recommended by World Health Organization guidelines for drinking water samples with the exception of dissolved oxygen and pH which exceeded the World Health Organization standards. Based on these findings, recommendation is made to responsible bodies of Negale Arsi woreda to implement effective water management and treatment methods to produce of drinking water at the area.