Assessment of the effect of season and location on microbiological and physicochemical quality of livestock drinking water in Ginchi watershed, Ethiopia

This study was conducted at Ginchi watershed in Oromia Regional State, Ethiopia to evaluate the physical, chemical and microbiological quality of livestock drinking waters during dry, short rain and wet seasons. Purposive sampling technique was used to obtain samples. Data were collected and analyzed using descriptive statistics. The analysis showed that the overall mean concentrations (mg/l) were 298.33 TDS, 8.0 pH, 15.78 Na, 2.9 K,128.22 CaCO , 40.89 Ca, 6.32 Mg, 0.26 F, 5.38 Cl, 0.03 NO , 5.68 NO , 2.67 CO 146 alkalinity, 3 2 3 3, 172.83 HCO , 3.42 SO and 0.07 boron. The pH of the water was basic, ranging from 7.8 to 8.2, which is within 34 the normal range for pH in surface water systems (6.5 to 8.5). The waters exhibited a general ionic dominance pattern of Ca > Na > Mg > K. The water was moderately hard to hard (range of hardness 80–170 mg/l CaCO3) with high turbidity due to traditional farming practices, which resulted in large quantities of topsoil runoff ending up in the river after rains. Trace metal levels were low suggesting low metal contamination of the rivers. The dominance of chloride over sulphate could probably be due to domestic activities resulting from fertilizer use, household effluents and other anthropogenic point sources. The TDS varied (P<0.05) between dry, short rain and wet seasons. The wet season showed significantly (P<0.05) lower value for hardness. Ca varied (P<0.05) between short rain and wet seasons, as well as between wet and dry seasons. Alkalinity varied (P<0.001) markedly between wet and dry seasons and between short rain and wet seasons (P<0.05). A significant (P<0.05) variation was also observed for bicarbonate between short rain and wet and wet and dry seasons. Effect of location was significant for K between low and high altitudes. The overall mean total coliform level was 1101.73±114.99 cfu/100 ml. Total coliform count was higher (P<0.05) in wet season and no variation (P>0.05) was observed between locations. From results of this study, the microbial quality of water was observed to be poor due to direct contamination by animal and human excreta and other activities such as washing of clothes. From both livestock and human health point view, consumption of this coli- form polluted water should be avoided.