The impact of effluents from Woliso Soap and Detergent Factory on Werabo River, South West Shewa district, Oromia, Ethiopia

• Impact of Effluents from Woliso Soap and Detergent Factory on Werabo River The study was assessed. • Werabo River has affected by the Effluents released from Woliso Soap and Detergent Factory. • The Water quality Index of the sampled river site were laid in the category of poor and very poor water quality. The discharge of industrial effluents into water bodies poses significant risks to aquatic ecosystems and human health. This study examines how the Werabo River in Woliso town, Oromia, Ethiopia, is affected by wastewater from the Woliso soap and detergent factory. In this study the level of pollution caused by the factory’s effluent and its effects on the ecological and socio-economic aspects of the local area were evaluated. To achieve this aims, water samples were collected at several points along the Werabo River, including the point where the manufacturing effluent joins the river. The samples were analyzed for various physicochemical parameters, and the water quality index (WQI) was calculated to assess the overall water quality. Additionally, socio-economic surveys and interviews were conducted to gather the local community’s perspectives on the pollution and its consequences. The findings showed that the levels of nitrate, phosphate, sodium, potassium, oil-grease, electrical conductivity (EC), salinity, dissolved oxygen (DO), temperature, pH, and total dissolved solids (TDS) were significantly higher at site II (the effluent discharge point) compared to upstream water samples. Statistically significant differences (p < 0.05) were observed between the three sampling sites based on the measured parameters. The WQI results showed that the water samples collected during the rainy season (WQI = 179.5) and the spring (WQI = 231) were classified as poor and very poor water quality status, respectively. The socio-economic survey also highlighted the severe health, social, and economic impacts of the wastewater discharge on the local community, particularly to the users of the studied river. The environmental and socioeconomic effects of the wastewater discharge into the Werabo River from the Woliso soap and detergent industry are significantly highlighted by this study. The findings underscore the need for improved industrial waste management and offer important information for policymakers and stakeholders to develop effective pollution control measures and strategies for sustainable water resource management.