Physico-chemical pollution pattern along Akaki River basin, Addis Ababa, Ethiopia

The present study focuses on the analysis of physico-chemical parameters: electrical conductivity, nitrate and phosphate in the Akaki River basin of Addis Ababa, Ethiopia. These secondary water quality parameters were obtained from two different sources: the surface water quality data both for Little and Great Akaki were retrieved from Addis Ababa Environmental Protection Agency (AAEPA). Whereas, the groundwater quality data for four water wells were obtained from Addis Ababa Water and Sewerage Authority (AAWSA). These water quality parameters have been determined in order to assess the pollution levels of Akaki River basin. The values of the parameters have been evaluated with respect to the maximum acceptable standard level of WHO (World Health Organization) for surface and drinking water. The outcome of the study observed absence of spatial and temporal pattern both on surface and groundwater but displayed a huge variation. The result also showed increasing concentration and variation of all parameters inside and outside the city of Addis Ababa with increasing industrialization and urbanization. Comparison also showed that the little Akaki is highly polluted as compared to Great Akaki River. The ground water chemistry also showed a high phosphate load in all of the productive wells. On the contrary, all the wells displayed nitrate level below WHO standard and they are free from Nitrate. KEY WORDS: Addis Ababa, Ethiopia, Physico-chemical, Little and Great Akaki, AAEPA, AAWSA, Spatial, temporal