The Kebena River traverses Addis Ababa from north to south, The river starts upstreamrnfrom a scarcely populated area and goes to the south through the densely populated areas.rnThe difference in ionic compositions as one goes from upstream to down stream is then anrnindication of human impact on the quality of water. The geogenic ions, which arernintroduced from the natural environment through which the water passes, and thernanthropogenic ions, which mainly enter into the water by the action of man, have beenrndetermined . The pH, conductivity, alkalinity, the chemical oxygen demand (COD),rnammonium, nitrite, nitrate, phosphate, sulfate, chloride, fluoride, sodium , potassium,rnmagnesium , calcium ions and silica have been determined from three different samplingrnsites, which represent upstream, midstream and downstream using standard methods ofrnanalysis.rnTime and space dependence of ionic composition has been studied starting from the end ofrnthe rain season (September, 2000) to the beginning of the small rain (April, 2001). The diyrnseason dominates in between. The increase in concentration of the anthropogenic ions asrnnitrate, nitrite, ammonium, phosphate, COD, and chloride, as one goes from upstream torndownstream through the highly populated areas and the increase in these ions as the rainrnceased and the surface runoff decreased were very good indications of the deterioration ofrnwater quality by human activities; by direct disposal of liquid and solid wastes to the river The Addis Ababa city solid waste disposal site is the landfill at Kore (Jimma Road). Twornsamples were taken to determine the ionic composition of the runoff from this landfill.rnEmphasis was given for trace elements, especially cadmium, lead, copper, and zinc,rndifferential pulse stripping voltammetry (DPSV) was used for their determination. The tracernelements (Cu, Pb, Cd and Zn) were not detected using DPSV, which has a detection limit ofrn1O'7-1O'8 M.